Another clean up, and add some new weapon speech.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@6439 c06c8d41-db1a-0410-9941-cceddc491573

32 files changed, 306 insertions, 231 deletions

diff --git a/crawl-ref/README.txt b/crawl-ref/README.txt
index e9010dbf7d..e6b9749d63 100644
--- a/crawl-ref/README.txt
+++ b/crawl-ref/README.txt
@@ -25,9 +25,9 @@ If you'd like to dive in immediately, your best bets are to
 * read quickstart.txt (in the /docs directory), or
 * for studious readers, browse the manual (see below for all doc files).
 
-Additionally, you may want to print out the file keys.pdf from the /docs
-folder. Besides a full list of command keys (don't bother with it), it contains 
-two pages of help for new players.
+If you're used to playing an older version, you might want to print out the 
+file key_changes.pdf from the /docs for an easy reference of new commands
+and changed key settings.
 Note that you can read quickstart.txt and the manual when playing; pressing '?' 
 brings up a menu for that.
 
@@ -53,10 +53,12 @@ read in-game by bringing up the help menu with '?'):
 * aptitudes.txt      Some numbers defining certain aspects of the races.
                      Helpful, but not needed for winning.
 * quickstart.txt     A short introduction for new players.
+* quickstart.pdf     The same file, in pdf format.
 * ssh_guide.txt      An elaborate introduction on how to get internet play
                      to work. For Windows only.
-* keys.pdf           A printable document, listing all commands and it also
-                     contains a very short guide for new players.
+* tiles_help.txt     An explanation of the Tiles interface.
+* key_changes.pdf    A printable document, listing all new commands and 
+                     changed key settings.
 
 The settings/ folder contains, among others, the following files:
 
diff --git a/crawl-ref/settings/messages.txt b/crawl-ref/settings/messages.txt
index 1fe894831f..5227d46a20 100644
--- a/crawl-ref/settings/messages.txt
+++ b/crawl-ref/settings/messages.txt
@@ -35,5 +35,5 @@ msc = darkgrey:You start (resting|searching)
 msc = darkgrey:Unknown command
 msc = darkgrey:disappears in a puff of smoke
 #
-msc = darkgrey:miss(es)? (the|you|it)
+msc = darkgrey:plain:miss(es)? (the|you|it)
 msc = darkgrey:but (do no|doesn't do any) damage
diff --git a/crawl-ref/source/abyss.cc b/crawl-ref/source/abyss.cc
index 2ef221a30a..e3e850af08 100644
--- a/crawl-ref/source/abyss.cc
+++ b/crawl-ref/source/abyss.cc
@@ -231,7 +231,7 @@ static void _generate_area(int gx1, int gy1, int gx2, int gy2,
     for (int i = gx1; i <= gx2; i++)
         for (int j = gy1; j <= gy2; j++)
         {
-            if (grd[i][j] == DNGN_UNSEEN && random2(100) <= thickness)
+            if (grd[i][j] == DNGN_UNSEEN && x_chance_in_y(thickness + 1, 100))
             {
                 grd[i][j] = DNGN_FLOOR;
 
diff --git a/crawl-ref/source/acr.cc b/crawl-ref/source/acr.cc
index 80e55b8fc9..2e7a26b559 100644
--- a/crawl-ref/source/acr.cc
+++ b/crawl-ref/source/acr.cc
@@ -2851,7 +2851,7 @@ static void _decrement_durations()
 
             // Note the beauty of Trog!  They get an extra save that's at
             // the very least 20% and goes up to 100%.
-            if (you.religion == GOD_TROG && you.piety > random2(150)
+            if (you.religion == GOD_TROG && x_chance_in_y(you.piety, 150)
                 && !player_under_penance())
             {
                 mpr("Trog's vigour flows through your veins.");
@@ -2949,7 +2949,7 @@ static void _decrement_durations()
         // to even start rotting right now, but that could be changed. -- bwr
         if (you.species == SP_MUMMY)
             you.rotting = 0;
-        else if (random2(20) <= (you.rotting - 1))
+        else if (x_chance_in_y(you.rotting, 20))
         {
             mpr("You feel your flesh rotting away.", MSGCH_WARN);
             ouch(1, 0, KILLED_BY_ROTTING);
@@ -2980,7 +2980,7 @@ static void _decrement_durations()
 
     if (you.duration[DUR_POISONING] > 0)
     {
-        if (random2(5) <= (you.duration[DUR_POISONING] - 1))
+        if (x_chance_in_y(you.duration[DUR_POISONING], 5))
         {
             if (you.duration[DUR_POISONING] > 10 && random2(you.duration[DUR_POISONING]) >= 8)
             {
@@ -3096,15 +3096,15 @@ static void _world_reacts()
 
     run_environment_effects();
 
-    if ( !you.cannot_act() && !player_mutation_level(MUT_BLURRY_VISION)
-         && random2(50) < you.skills[SK_TRAPS_DOORS] )
+    if (!you.cannot_act() && !player_mutation_level(MUT_BLURRY_VISION)
+        && x_chance_in_y(you.skills[SK_TRAPS_DOORS], 50))
     {
-        search_around(false); // check nonadjacent squares too
+        search_around(false); // Check nonadjacent squares too.
     }
 
     stealth = check_stealth();
 
-#if 0
+#ifdef DEBUG_STEALTH
     // Too annoying for regular diagnostics.
     mprf(MSGCH_DIAGNOSTICS, "stealth: %d", stealth );
 #endif
diff --git a/crawl-ref/source/beam.cc b/crawl-ref/source/beam.cc
index 7ec80af5c5..def9eea4b0 100644
--- a/crawl-ref/source/beam.cc
+++ b/crawl-ref/source/beam.cc
@@ -742,7 +742,7 @@ dice_def calc_dice( int num_dice, int max_damage )
         // Divide the damage among the dice, and add one
         // occasionally to make up for the fractions. -- bwr
         ret.size  = max_damage / num_dice;
-        ret.size += (random2( num_dice ) < max_damage % num_dice);
+        ret.size += x_chance_in_y(max_damage % num_dice, num_dice);
     }
 
     return (ret);
@@ -4054,7 +4054,8 @@ static int _affect_player( bolt &beam, item_def *item )
     if (you.equip[EQ_BODY_ARMOUR] != -1)
     {
         if (!player_light_armour(false) && one_chance_in(4)
-            && random2(1000) <= item_mass( you.inv[you.equip[EQ_BODY_ARMOUR]] ))
+            && x_chance_in_y(item_mass(you.inv[you.equip[EQ_BODY_ARMOUR]]) + 1,
+                             1000))
         {
             exercise( SK_ARMOUR, 1 );
         }
@@ -4106,8 +4107,8 @@ static int _affect_player( bolt &beam, item_def *item )
         else if (item->special == SPMSL_POISONED)
         {
             if (!player_res_poison()
-                && (hurted || (beam.ench_power == AUTOMATIC_HIT
-                               && random2(100) < 90 - (3 * player_AC()))))
+                && (hurted || beam.ench_power == AUTOMATIC_HIT
+                              && x_chance_in_y(90 - 3 * player_AC(), 100)))
             {
                 poison_player( 1 + random2(3) );
                 was_affected = true;
@@ -4115,7 +4116,7 @@ static int _affect_player( bolt &beam, item_def *item )
         }
         else if (item->special == SPMSL_CURARE)
         {
-            if (random2(100) < 90 - (3 * player_AC()))
+            if (x_chance_in_y(90 - 3 * player_AC(), 100))
             {
                 curare_hits_player( _beam_ouch_agent(beam), 1 + random2(3) );
                 was_affected = true;
@@ -4736,22 +4737,20 @@ static int _affect_monster(bolt &beam, monsters *mon, item_def *item)
                 int num_levels = 0;
                 // ench_power == AUTOMATIC_HIT if this is a poisoned needle.
                 if (beam.ench_power == AUTOMATIC_HIT
-                    && random2(100) < 90 - (3 * mon->ac))
+                    && x_chance_in_y(90 - 3 * mon->ac, 100))
                 {
                     num_levels = 2;
                 }
                 else if (random2(hurt_final) - random2(mon->ac) > 0)
-                {
                     num_levels = 1;
-                }
 
                 int num_success = 0;
                 if (YOU_KILL(beam.thrower))
                 {
                     const int skill_level = _name_to_skill_level(beam.name);
-                    if ( skill_level + 25 > random2(50) )
+                    if (x_chance_in_y(skill_level + 25, 50))
                         num_success++;
-                    if ( skill_level > random2(50) )
+                    if (x_chance_in_y(skill_level, 50))
                         num_success++;
                 }
                 else
diff --git a/crawl-ref/source/cloud.cc b/crawl-ref/source/cloud.cc
index 24b62e6977..9b01fa84d6 100644
--- a/crawl-ref/source/cloud.cc
+++ b/crawl-ref/source/cloud.cc
@@ -541,7 +541,7 @@ void in_a_cloud()
     case CLOUD_MIASMA:
         mpr("You are engulfed in a dark miasma.");
 
-        if (player_prot_life() > random2(3))
+        if (x_chance_in_y(player_prot_life(), 3))
             return;
 
         poison_player(1);
diff --git a/crawl-ref/source/dat/database/wpnnoise.txt b/crawl-ref/source/dat/database/wpnnoise.txt
index 3526bf7174..3821aa06f4 100644
--- a/crawl-ref/source/dat/database/wpnnoise.txt
+++ b/crawl-ref/source/dat/database/wpnnoise.txt
@@ -68,9 +68,11 @@ weapon_sings
 
 @The_weapon@ makes a painfully high-pitched squeak.
 
+@The_weapon@ sings an ear-splitting high note.
+
 @The_weapon@ sings a sudden staccato note.
 
-@The_weapon@ sings a catchy @tune_or_melody@.
+@The_weapon@ @sings_or_hums@ a catchy @tune_or_melody@.
 
 @The_weapon@ hums a slow waltz.
 
@@ -89,7 +91,7 @@ weapon_sings
 
 @The_weapon@ hums an eerie @tune_or_melody@.
 
-@The_weapon@ hums a slow and mournful tune.
+@The_weapon@ @sings_or_hums@ a slow and mournful tune.
 
 @The_weapon@ launches into yet another solo.
 
@@ -105,6 +107,8 @@ weapon_sings
 
 @The_weapon@ sings a little jingle.
 
+@The_weapon@ raucously launches into song.
+
 @The_weapon@ strikes up a funeral march.
 
 @The_weapon@ merrily whistles a melody.
@@ -127,6 +131,12 @@ In a hysterical voice, @the_weapon@ strikes up a march.
 
 @The_weapon@ @nearly_or_clearly@ @hits_or_misses@ the concert pitch.
 
+@The_weapon@ sings a song about @song_theme@.
+
+@The_weapon@ composes a hymn about @song_theme@.
+
+@The_weapon@ composes a ballad about your adventures.
+
 #imitates instruments
 @The_weapon@ makes a twanging sound.
 
@@ -179,6 +189,8 @@ In a hysterical voice, @the_weapon@ strikes up a march.
 
 @The_weapon@ tries to improvise rhymes, and fails miserably.
 
+@The_weapon@ asks you for a rhyme on '@rhyme_word@'.
+
 @The_weapon@ complains about @double_or_triple@ swords.
 
 @The_weapon@ derides short swords.
@@ -187,6 +199,12 @@ In a hysterical voice, @the_weapon@ strikes up a march.
 
 @The_weapon@ chants, "Rather stab than club, rather slice than rub!"
 
+@The_weapon@ says, "Whips just don't cut it for me, don't you agree?"
+
+@The_weapon@ muses on the connection between 'duet' and 'duel'.
+
+@Your_weapon@ wails, "I am too young to rust!"
+
 # end Singing Sword
 %%%%
 ############################################################
@@ -210,9 +228,9 @@ weapon_talks
 
 @Your_weapon@ cheers you on.
 
-@Your_weapon@ calls out a warning!
+@Your_weapon@ intones a prayer.
 
-@Your_weapon@ hurls insults at you.
+@Your_weapon@ calls out a warning!
 
 @Your_weapon@ chatters happily.
 
@@ -241,11 +259,9 @@ weapon_talks
 
 @Your_weapon@ amuses itself with detailed descriptions of past executions.
 
-@Your_weapon@ wails, "I am too young to rust!"
-
 @Your_weapon@ wishes everyone in the dungeon @unpleasant_or_sudden@ @demise_or_death@.
 
-@Your_weapon@ fumes, "Being battered, bent and broken sure is better than this boredom!"
+@Your_weapon@ fumes, "Being battered, bent, and broken sure is better than this boredom!"
 
 @Your_weapon@ yells, "No battle, no fun!"
 
@@ -263,12 +279,36 @@ weapon_talks
 
 @Your_weapon@ shouts, "Left! No, no, right!".
 
-@Your_weapon@ says, "How I wish you were a better fighter."
+@Your_weapon@ sighs, "How I wish you were a better fighter."
 
 @Your_weapon@ grouses, "Could you please kill something?  I'm itching all over."
 
 @Your_weapon@ shouts, "Make war, not love!"
 
+@Your_weapon@ cries out, "You certainly can't call me dull!"
+
+@Your_weapon@ tells you the story of its previous owner's @demise_or_death@.
+
+@Your_weapon@ brightly announces, "I've got so much to tell you!"
+
+@Your_weapon@ comments on your fighting techniques.
+
+@Your_weapon@ says, "You could say something too, you know."
+
+@Your_weapon@ complains, "Are you always this @silent@?"
+
+@Your_weapon@ says, "Why don't you say something for a change?"
+
+@Your_weapon@ asks, "Did you take a vow of silence?"
+
+@Your_weapon@ shouts a battle cry!
+
+@Your_weapon@ shouts, "Onwards!  It's kill or die!"
+
+@Your_weapon@ says, "You can tell me everything!  I can keep a secret!"
+
+@Your_weapon@ grouses, "Silence can be so depressing."
+
 #makes noises
 @Your_weapon@ growls menacingly.
 
@@ -310,8 +350,6 @@ weapon_talks
 
 @Your_weapon@ yawns loudly.
 
-@Your_weapon@ intones a prayer.
-
 @Your_weapon@ cries out!
 
 @Your_weapon@ swears loudly.
@@ -346,6 +384,8 @@ weapon_talks
 
 @Your_weapon@ yelps loudly!
 
+@Your_weapon@ cheers!
+
 @Your_weapon@ lets out a series of bird calls.
 
 # end weapon chatter
@@ -474,6 +514,12 @@ waltz
 
 menuet
 %%%%
+sings_or_hums
+
+sings
+
+hums
+%%%%
 an_aria_or_fugue
 
 an aria
@@ -522,3 +568,31 @@ double
 
 triple
 %%%%
+rhyme_word
+
+fountain of blood
+
+killing spree
+
+battlefield
+%%%%
+song_theme
+
+battle and fame
+
+death and destruction
+
+the glory of death
+%%%%
+silent
+
+uncommunicative
+
+taciturn
+
+quiet
+
+silent
+
+boring
+%%%%
\ No newline at end of file
diff --git a/crawl-ref/source/decks.cc b/crawl-ref/source/decks.cc
index de5e5c5a62..6298404b97 100644
--- a/crawl-ref/source/decks.cc
+++ b/crawl-ref/source/decks.cc
@@ -2225,7 +2225,7 @@ static void _deepen_water(const coord_def& center, int radius)
         const coord_def p = *ri;
         if (grd(p) == DNGN_SHALLOW_WATER
             && p != you.pos()
-            && random2(8) < 1 + count_neighbours(p.x, p.y, DNGN_DEEP_WATER))
+            && x_chance_in_y(1+count_neighbours(p.x, p.y, DNGN_DEEP_WATER), 8))
         {
             dungeon_terrain_changed(p, DNGN_DEEP_WATER);
         }
diff --git a/crawl-ref/source/describe.cc b/crawl-ref/source/describe.cc
index 2b122cbc63..5adabd8e35 100644
--- a/crawl-ref/source/describe.cc
+++ b/crawl-ref/source/describe.cc
@@ -743,7 +743,7 @@ static std::string _describe_demon(const monsters &mons)
 
     description << ".";
 
-    if (random2(40) < 3)
+    if (x_chance_in_y(3, 40))
     {
         if (player_can_smell())
         {
diff --git a/crawl-ref/source/dungeon.cc b/crawl-ref/source/dungeon.cc
index 927e8fc600..622f97ef5d 100644
--- a/crawl-ref/source/dungeon.cc
+++ b/crawl-ref/source/dungeon.cc
@@ -7698,7 +7698,7 @@ bool dgn_region::overlaps(const map_mask &mask) const
 
 coord_def dgn_region::random_edge_point() const
 {
-    return random2(size.x + size.y) < size.x ?
+    return x_chance_in_y(size.x, size.x + size.y) ?
                   coord_def( pos.x + random2(size.x),
                              coinflip()? pos.y : pos.y + size.y - 1 )
                 : coord_def( coinflip()? pos.x : pos.x + size.x - 1,
diff --git a/crawl-ref/source/effects.cc b/crawl-ref/source/effects.cc
index 26d2847bef..db5f40a017 100644
--- a/crawl-ref/source/effects.cc
+++ b/crawl-ref/source/effects.cc
@@ -2474,9 +2474,9 @@ void handle_time(long time_delta)
         }
     }
 
-    // Adjust the player's stats if s/he has the deterioration mutation
+    // Adjust the player's stats if s/he has the deterioration mutation.
     if (player_mutation_level(MUT_DETERIORATION)
-        && random2(200) <= player_mutation_level(MUT_DETERIORATION) * 5 - 2)
+        && x_chance_in_y(player_mutation_level(MUT_DETERIORATION) * 5 - 1, 200))
     {
         lose_stat(STAT_RANDOM, 1, false, "deterioration mutation");
     }
@@ -2531,13 +2531,13 @@ void handle_time(long time_delta)
         // roll.)
         if (is_sanctuary(you.x_pos, you.y_pos)
             && you.magic_contamination >= 5
-            && random2(25) <= you.magic_contamination)
+            && x_chance_in_y(you.magic_contamination + 1, 25))
         {
             mpr("Your body momentarily shudders from a surge of wild "
                 "energies until Zin's power calms it.", MSGCH_GOD);
         }
         else if (you.magic_contamination >= 5
-                 && random2(25) <= you.magic_contamination)
+                 && x_chance_in_y(you.magic_contamination + 1, 25))
         {
             mpr("Your body shudders with the violent release "
                 "of wild energies!", MSGCH_WARN);
@@ -2654,11 +2654,10 @@ void handle_time(long time_delta)
     }
 
     // Check to see if an upset god wants to do something to the player.
-    // jmf: moved huge thing to religion.cc
     handle_god_time();
 
     if (player_mutation_level(MUT_SCREAM)
-        && (random2(100) <= 2 + player_mutation_level(MUT_SCREAM) * 3))
+        && x_chance_in_y(3 + player_mutation_level(MUT_SCREAM) * 3, 100))
     {
         yell(true);
     }
diff --git a/crawl-ref/source/fight.cc b/crawl-ref/source/fight.cc
index 0bbfc47f96..21fcd0613c 100644
--- a/crawl-ref/source/fight.cc
+++ b/crawl-ref/source/fight.cc
@@ -1477,7 +1477,7 @@ void melee_attack::player_weapon_auto_id()
         && weapon->base_type == OBJ_WEAPONS
         && !is_range_weapon( *weapon )
         && !item_ident( *weapon, ISFLAG_KNOW_PLUSES )
-        && random2(100) < you.skills[ wpn_skill ])
+        && x_chance_in_y(you.skills[ wpn_skill ], 100))
     {
         set_ident_flags( *weapon, ISFLAG_KNOW_PLUSES );
         mprf("You are wielding %s.", weapon->name(DESC_NOCAP_A).c_str());
@@ -1542,7 +1542,7 @@ int melee_attack::player_stab(int damage)
         if (mons_is_sleeping(def))
         {
             // Sleeping moster wakes up when stabbed but may be groggy.
-            if (random2(200) <= you.skills[SK_STABBING] + you.dex)
+            if (x_chance_in_y(you.skills[SK_STABBING] + you.dex + 1, 200))
             {
                 int stun = random2( you.dex + 1 );
 
@@ -2319,8 +2319,8 @@ bool melee_attack::apply_damage_brand()
         break;
     }
     case SPWPN_PAIN:
-        if (defender->res_negative_energy()
-            && random2(8) <= attacker->skill(SK_NECROMANCY))
+        if (!defender->res_negative_energy()
+            && x_chance_in_y(attacker->skill(SK_NECROMANCY) + 1, 8))
         {
             if (defender_visible)
             {
@@ -2350,7 +2350,7 @@ bool melee_attack::apply_damage_brand()
         if (mons_class_is_confusable(def->type)
             && hdcheck >= defender->get_experience_level())
         {
-            // declaring these just to pass to the enchant function
+            // Declaring these just to pass to the enchant function.
             bolt beam_temp;
             beam_temp.thrower =
                 attacker->atype() == ACT_PLAYER? KILL_YOU : KILL_MON;
@@ -2586,13 +2586,13 @@ void melee_attack::player_apply_staff_damage()
 
     case STAFF_POISON:
     {
-        // cap chance at 30% -- let staff of Olgreb shine
+        // Cap chance at 30% -- let staff of Olgreb shine.
         int temp_rand = damage_done + you.skills[SK_POISON_MAGIC];
 
         if (temp_rand > 30)
             temp_rand = 30;
 
-        if (random2(100) < temp_rand)
+        if (x_chance_in_y(temp_rand, 100))
         {
             // Poison monster message needs to arrive after hit message.
             emit_nodmg_hit_message();
@@ -2605,7 +2605,7 @@ void melee_attack::player_apply_staff_damage()
         if (mons_res_negative_energy(def))
             break;
 
-        if (random2(8) <= you.skills[SK_NECROMANCY])
+        if (x_chance_in_y(you.skills[SK_NECROMANCY] + 1, 8))
         {
             special_damage = player_staff_damage(SK_NECROMANCY);
 
@@ -2876,8 +2876,8 @@ void melee_attack::player_stab_check()
 
     bool roll_needed = true;
     int roll = 155;
-    // This ordering is important!
 
+    // This ordering is important!
     switch (unchivalric)
     {
     default:
@@ -2919,7 +2919,10 @@ void melee_attack::player_stab_check()
 
     // See if we need to roll against dexterity / stabbing.
     if (stab_attempt && roll_needed)
-        stab_attempt = (random2(roll) <= you.skills[SK_STABBING] + you.dex);
+    {
+        stab_attempt = x_chance_in_y(you.skills[SK_STABBING] + you.dex + 1,
+                                     roll);
+    }
 }
 
 void melee_attack::player_apply_attack_delay()
@@ -3500,7 +3503,7 @@ void melee_attack::check_defender_train_armour()
         return;
 
     const item_def *arm = defender->slot_item(EQ_BODY_ARMOUR);
-    if (arm && coinflip() && random2(1000) <= item_mass(*arm))
+    if (arm && coinflip() && x_chance_in_y(item_mass(*arm) + 1, 1000))
         defender->exercise(SK_ARMOUR, coinflip()? 2 : 1);
 }
 
@@ -3707,7 +3710,7 @@ void melee_attack::mons_apply_attack_flavour(const mon_attack_def &attk)
         if (mons_is_summoned(def))
             break;
 
-        if (defender->res_negative_energy() > random2(3))
+        if (x_chance_in_y(defender->res_negative_energy(), 3))
             break;
 
         if (defender->stat_hp() < defender->stat_maxhp())
diff --git a/crawl-ref/source/food.cc b/crawl-ref/source/food.cc
index 6c92065f09..b915203df7 100644
--- a/crawl-ref/source/food.cc
+++ b/crawl-ref/source/food.cc
@@ -1773,7 +1773,7 @@ void vampire_nutrition_per_turn(const item_def &corpse, int feeding)
                 // Human blood gives extra healing during feeding.
                 if (hp_amt >= duration)
                     hp_amt /= duration;
-                else if (random2(duration) < hp_amt)
+                else if (x_chance_in_y(hp_amt, duration))
                     hp_amt = 1;
 
                 _heal_from_food(hp_amt, 0, one_chance_in(duration/2),
@@ -2259,7 +2259,7 @@ static int _determine_chunk_effect(int which_chunk_type, bool rotten_chunk)
     // saprovores get rotting meat effect from clean chunks, since they
     // love rotting meat.
     if (wearing_amulet(AMU_THE_GOURMAND)
-        && random2(GOURMAND_MAX) < you.duration[DUR_GOURMAND])
+        && x_chance_in_y(you.duration[DUR_GOURMAND], GOURMAND_MAX))
     {
         if (player_mutation_level(MUT_SAPROVOROUS) == 3)
         {
diff --git a/crawl-ref/source/ghost.cc b/crawl-ref/source/ghost.cc
index b4f2788ab7..728489b8f2 100644
--- a/crawl-ref/source/ghost.cc
+++ b/crawl-ref/source/ghost.cc
@@ -533,6 +533,7 @@ void ghost_demon::find_extra_ghosts( std::vector<ghost_demon> &gs, int n )
     find_transiting_ghosts(gs, n);
 }
 
+// Returns the number of extra ghosts allowed on the level.
 int ghost_demon::n_extra_ghosts()
 {
     const int lev = you.your_level + 1;
@@ -554,15 +555,19 @@ int ghost_demon::n_extra_ghosts()
         return (0);
 
     // No multiple ghosts until level 9 of the main dungeon.
-    if ((lev < 9 && you.where_are_you == BRANCH_MAIN_DUNGEON)
-        || (subdepth < 2 && you.where_are_you == BRANCH_LAIR)
-        || (subdepth < 2 && you.where_are_you == BRANCH_ORCISH_MINES))
+    if (lev < 9 && you.where_are_you == BRANCH_MAIN_DUNGEON
+        || subdepth < 2 && you.where_are_you == BRANCH_LAIR
+        || subdepth < 2 && you.where_are_you == BRANCH_ORCISH_MINES)
+    {
         return (0);
+    }
 
     if (you.where_are_you == BRANCH_LAIR
         || you.where_are_you == BRANCH_ORCISH_MINES
-        || (you.where_are_you == BRANCH_MAIN_DUNGEON && lev < 15))
+        || you.where_are_you == BRANCH_MAIN_DUNGEON && lev < 15)
+    {
         return (1);
+    }
 
-    return 1 + (random2(20) < lev) + (random2(40) < lev);
+    return (1 + x_chance_in_y(lev, 20) + x_chance_in_y(lev, 40));
 }
diff --git a/crawl-ref/source/it_use3.cc b/crawl-ref/source/it_use3.cc
index a247b568f5..ef0ed9af09 100644
--- a/crawl-ref/source/it_use3.cc
+++ b/crawl-ref/source/it_use3.cc
@@ -223,7 +223,7 @@ void special_wielded()
         break;
 
     case SPWLD_SHADOW:
-        if (random2(8) <= player_spec_death())
+        if (x_chance_in_y(player_spec_death() + 1, 8))
         {
             create_monster(
                 mgen_data(MONS_SHADOW, BEH_FRIENDLY,
@@ -514,7 +514,7 @@ bool evoke_wielded()
 
                 your_spells( SPELL_OLGREBS_TOXIC_RADIANCE, power, false );
 
-                if (you.skills[SK_EVOCATIONS] >= random2(10))
+                if (x_chance_in_y(you.skills[SK_EVOCATIONS] + 1, 10))
                     your_spells( SPELL_VENOM_BOLT, power, false );
                 break;
 
@@ -563,7 +563,7 @@ bool evoke_wielded()
         else if (wpn.sub_type == STAFF_CHANNELING)
         {
             if (you.magic_points < you.max_magic_points
-                && you.skills[SK_EVOCATIONS] + 10 >= random2(40))
+                && x_chance_in_y(you.skills[SK_EVOCATIONS] + 11, 40))
             {
                 mpr("You channel some magical energy.");
                 inc_mp( 1 + random2(3), false );
@@ -695,7 +695,7 @@ bool evoke_wielded()
 
 static bool efreet_flask(void)
 {
-    bool friendly = (you.skills[SK_EVOCATIONS] / 3 + 10 > random2(20));
+    bool friendly = x_chance_in_y(10 + you.skills[SK_EVOCATIONS] / 3, 20);
 
     mpr("You open the flask...");
 
@@ -960,7 +960,7 @@ static bool box_of_beasts()
 
     mpr("You open the lid...");
 
-    if (random2(100) < 60 + you.skills[SK_EVOCATIONS])
+    if (x_chance_in_y(60 + you.skills[SK_EVOCATIONS], 100))
     {
         monster_type beasty = MONS_PROGRAM_BUG;
 
diff --git a/crawl-ref/source/item_use.cc b/crawl-ref/source/item_use.cc
index 568645fc89..af14f7570b 100644
--- a/crawl-ref/source/item_use.cc
+++ b/crawl-ref/source/item_use.cc
@@ -2242,7 +2242,7 @@ bool throw_it(bolt &pbolt, int throw_2, bool teleport, int acc_bonus,
         {
             if (!teleport
                 && !item_ident(you.inv[throw_2], ISFLAG_KNOW_PLUSES)
-                && random2(100) < shoot_skill)
+                && x_chance_in_y(shoot_skill, 100))
             {
                 set_ident_flags( item, ISFLAG_KNOW_PLUSES );
                 set_ident_flags( you.inv[throw_2], ISFLAG_KNOW_PLUSES );
@@ -2251,7 +2251,7 @@ bool throw_it(bolt &pbolt, int throw_2, bool teleport, int acc_bonus,
                      you.inv[throw_2].name(DESC_NOCAP_A).c_str());
             }
         }
-        else if (!teleport && random2(100) < shoot_skill)
+        else if (!teleport && x_chance_in_y(shoot_skill, 100))
         {
             item_def& weapon = you.inv[you.equip[EQ_WEAPON]];
             set_ident_flags(weapon, ISFLAG_KNOW_PLUSES);
@@ -2414,7 +2414,7 @@ bool throw_it(bolt &pbolt, int throw_2, bool teleport, int acc_bonus,
         // ID check
         if (!teleport
             && !item_ident(you.inv[throw_2], ISFLAG_KNOW_PLUSES)
-            && random2(100) < you.skills[SK_THROWING])
+            && x_chance_in_y(you.skills[SK_THROWING], 100))
         {
             set_ident_flags( item, ISFLAG_KNOW_PLUSES );
             set_ident_flags( you.inv[throw_2], ISFLAG_KNOW_PLUSES );
@@ -3936,7 +3936,7 @@ bool enchant_weapon( enchant_stat_type which_stat, bool quiet, item_def &wpn )
 
     // Even if not affected, it may be uncursed.
     if (!is_enchantable_weapon(wpn, false)
-        || enchant_level >= 4 && random2(9) < enchant_level)
+        || enchant_level >= 4 && x_chance_in_y(enchant_level, 9))
     {
         if (is_cursed)
         {
@@ -4060,7 +4060,7 @@ bool enchant_armour( int &ac_change, bool quiet, item_def &arm )
 
     // Even if not affected, it may be uncursed.
     if (!is_enchantable_armour(arm, false)
-        || arm.plus >= 3 && random2(8) < arm.plus)
+        || arm.plus >= 3 && x_chance_in_y(arm.plus, 8))
     {
         if (is_cursed)
         {
diff --git a/crawl-ref/source/items.cc b/crawl-ref/source/items.cc
index ff0731d68f..e373e6f93b 100644
--- a/crawl-ref/source/items.cc
+++ b/crawl-ref/source/items.cc
@@ -172,12 +172,12 @@ static int _cull_items(void)
 
     int first_cleaned = NON_ITEM;
 
-    // 2. avoid shops by avoiding (0,5..9)
-    // 3. avoid monster inventory by iterating over the dungeon grid
+    // 2. Avoid shops by avoiding (0,5..9).
+    // 3. Avoid monster inventory by iterating over the dungeon grid.
     for (int x = 5; x < GXM; x++)
         for (int y = 5; y < GYM; y++)
         {
-            // 1. not near player!
+            // 1. Not near player!
             if (x > you.x_pos - 9 && x < you.x_pos + 9
                 && y > you.y_pos - 9 && y < you.y_pos + 9)
             {
@@ -186,23 +186,23 @@ static int _cull_items(void)
 
             int next;
 
-            // iterate through the grids list of items:
+            // Iterate through the grids list of items.
             for (int item = igrd[x][y]; item != NON_ITEM; item = next)
             {
                 next = mitm[item].link; // in case we can't get it later.
 
-                if (_item_ok_to_clean(item) && random2(100) < 15)
+                if (_item_ok_to_clean(item) && x_chance_in_y(15, 100))
                 {
                     const item_def& obj(mitm[item]);
                     if (is_fixed_artefact(obj))
                     {
-                        // 7. move uniques to abyss
+                        // 7. Move uniques to abyss.
                         set_unique_item_status( OBJ_WEAPONS, obj.special,
                                                 UNIQ_LOST_IN_ABYSS );
                     }
                     else if (is_unrandom_artefact(obj))
                     {
-                        // 9. unmark unrandart
+                        // 9. Unmark unrandart.
                         const int z = find_unrandart_index(obj);
                         if (z != -1)
                             set_unrandart_exist(z, false);
@@ -213,7 +213,7 @@ static int _cull_items(void)
                     if (first_cleaned == NON_ITEM)
                         first_cleaned = item;
                 }
-            } // end for item
+            }
 
         }
 
diff --git a/crawl-ref/source/makeitem.cc b/crawl-ref/source/makeitem.cc
index 4c52a30ec7..c27a6bf7a3 100644
--- a/crawl-ref/source/makeitem.cc
+++ b/crawl-ref/source/makeitem.cc
@@ -864,12 +864,12 @@ static weapon_type _determine_weapon_subtype(int item_level)
         WPN_TRIPLE_SWORD
     };
 
-    if (item_level > 6 && random2(100) < (10 + item_level)
-        && one_chance_in(30))
+    if (item_level > 6 && one_chance_in(30)
+        && x_chance_in_y(10 + item_level, 100))
     {
         rc = RANDOM_ELEMENT(rare_subtypes);
     }
-    else if (random2(20) < 20 - item_level)
+    else if (x_chance_in_y(20 - item_level, 20))
         rc = RANDOM_ELEMENT(common_subtypes);
     else
     {
@@ -878,7 +878,7 @@ static weapon_type _determine_weapon_subtype(int item_level)
         {
             const int wpntype = random2(NUM_WEAPONS);
 
-            if (weapon_rarity(wpntype) > random2(10))
+            if (x_chance_in_y(weapon_rarity(wpntype), 10))
             {
                 rc = static_cast<weapon_type>(wpntype);
                 break;
@@ -893,7 +893,7 @@ static bool _try_make_weapon_artefact(item_def& item, int force_type,
                                       int item_level)
 {
     if (item.sub_type != WPN_CLUB && item_level > 2
-        && random2(4000) <= 100 + (item_level * 3))
+        && x_chance_in_y(101 + (item_level * 3), 4000))
     {
         // Make a randart or unrandart.
 
@@ -944,8 +944,8 @@ static bool _try_make_weapon_artefact(item_def& item, int force_type,
 
     // If it isn't an artefact yet, try to make a fixed artefact.
     if (item_level > 6
-        && random2(3000) <= 30 + (item_level * 3)
-        && one_chance_in(12))
+        && one_chance_in(12)
+        && x_chance_in_y(31 + (item_level * 3), 3000))
     {
 #ifdef DEBUG_DIAGNOSTICS
         mprf(MSGCH_DIAGNOSTICS, "Making fixed artefact.");
@@ -1175,8 +1175,11 @@ static brand_type _determine_weapon_brand(const item_def& item, int item_level)
 
     for (int count = 0; count < tries && rc == SPWPN_NORMAL; ++count)
     {
-        if (!(force_good || is_demonic(item) || random2(300) <= 100+item_level))
+        if (!force_good && !is_demonic(item)
+            && !x_chance_in_y(101 + item_level, 300))
+        {
             continue;
+        }
 
         // We are not guaranteed to have a special set by the end of this
         switch (item.sub_type)
@@ -1560,7 +1563,7 @@ static void _generate_weapon_item(item_def& item, bool allow_uniques,
     _weapon_add_racial_modifiers(item);
 
     if ((force_good || is_demonic(item) || forced_ego
-            || random2(200) <= 50 + item_level)
+            || x_chance_in_y(51 + item_level, 200))
         // Nobody would bother enchanting a mundane club.
         && item.sub_type != WPN_CLUB
         && item.sub_type != WPN_GIANT_CLUB
@@ -1792,7 +1795,7 @@ static void _generate_missile_item(item_def& item, int force_type,
     else
         item.quantity = 1 + random2(9) + random2(12) + random2(12) + random2(15);
 
-    if (10 + item_level >= random2(100))
+    if (x_chance_in_y(11 + item_level, 100))
         item.plus += random2(5);
 
     // elven arrows and dwarven bolts are quality items
@@ -1806,7 +1809,7 @@ static void _generate_missile_item(item_def& item, int force_type,
 static bool _try_make_armour_artefact(item_def& item, int force_type,
                                       int item_level)
 {
-    if (item_level > 2 && random2(4000) <= (100 + item_level * 3))
+    if (item_level > 2 && x_chance_in_y(101 + item_level * 3, 4000))
     {
         // Make a randart or unrandart.
 
@@ -2036,7 +2039,7 @@ static special_armour_type _determine_armour_ego(const item_def& item,
             break;
         case 3:
             // This is an odd limitation, but I'm not changing it yet.
-            if (force_type == OBJ_RANDOM && random2(50) <= 10 + item_level)
+            if (force_type == OBJ_RANDOM && x_chance_in_y(11 + item_level, 50))
                 rc = SPARM_ARCHMAGI;
             break;
         }
@@ -2103,16 +2106,19 @@ static void _generate_armour_item(item_def& item, bool allow_uniques,
         item.special = SPARM_NORMAL;
 
     if (force_good || forced_ego || item.sub_type == ARM_WIZARD_HAT
-        || 50 + item_level >= random2(250))
+        || x_chance_in_y(51 + item_level, 250))
     {
         // Make a good item...
         item.plus += random2(3);
 
-        if (item.sub_type <= ARM_PLATE_MAIL && 20 + item_level >= random2(300))
+        if (item.sub_type <= ARM_PLATE_MAIL
+            && x_chance_in_y(21 + item_level, 300))
+        {
             item.plus += random2(3);
+        }
 
         if (!no_ego
-            && (30 + item_level >= random2(350))
+            && x_chance_in_y(31 + item_level, 350)
             && (force_good
                 || forced_ego
                 || get_equip_race(item) != ISFLAG_ORCISH
@@ -2464,7 +2470,7 @@ static void _generate_book_item(item_def& item, int force_type,
             }
 
             if (!one_chance_in(100)
-                && random2(item_level+1) + 1 < book_rarity(item.sub_type))
+                && x_chance_in_y(book_rarity(item.sub_type)-1, item_level+1))
             {
                 item.sub_type = BOOK_DESTRUCTION; // continue trying
             }
@@ -2473,17 +2479,17 @@ static void _generate_book_item(item_def& item, int force_type,
                || item.sub_type == BOOK_MANUAL
                || book_rarity(item.sub_type) == 100);
 
-        // tome of destruction: rare!
-        if ( item_level > 10 && random2(7000) <= item_level + 20 )
+        // Tome of destruction: rare!
+        if (item_level > 10 && x_chance_in_y(21 + item_level, 7000))
             item.sub_type = BOOK_DESTRUCTION;
 
-        // skill manuals - also rare
-        if ( item_level >  6 && random2(4000) <= item_level + 20 )
+        // Skill manuals - also rare.
+        if (item_level > 6 && x_chance_in_y(21 + item_level, 4000))
             item.sub_type = BOOK_MANUAL;
     }
 
-    // Determine which skill for a manual
-    if ( item.sub_type == BOOK_MANUAL )
+    // Determine which skill for a manual.
+    if (item.sub_type == BOOK_MANUAL)
     {
         if (one_chance_in(4))
             item.plus = SK_SPELLCASTING + random2(NUM_SKILLS - SK_SPELLCASTING);
@@ -2532,8 +2538,8 @@ static bool _try_make_jewellery_unrandart(item_def& item, int force_type,
     if (item_level > 2
         && you.level_type != LEVEL_ABYSS
         && you.level_type != LEVEL_PANDEMONIUM
-        && random2(2000) <= 100 + (item_level * 3)
-        && one_chance_in(20))
+        && one_chance_in(20)
+        && x_chance_in_y(101 + item_level * 3, 2000))
     {
         // The old generation code did not respect force_type here.
         const int idx = find_okay_unrandart(OBJ_JEWELLERY, force_type);
@@ -2611,7 +2617,7 @@ static void _generate_jewellery_item(item_def& item, bool allow_uniques,
         {
             item.plus2 = 1 + (one_chance_in(3) ? random2(3) : random2avg(6, 2));
 
-            if (random2(25) < 9)        // 36% of such rings {dlb}
+            if (x_chance_in_y(9, 25))        // 36% of such rings {dlb}
             {
                 // make "ring of damage"
                 do_uncurse_item(item);
@@ -2623,7 +2629,7 @@ static void _generate_jewellery_item(item_def& item, bool allow_uniques,
 
     // All jewellery base types should now work. -- bwr
     if (allow_uniques && item_level > 2
-        && random2(4000) <= 100 + (item_level * 3))
+        && x_chance_in_y(101 + item_level * 3, 4000))
     {
         make_item_randart( item );
     }
@@ -2736,7 +2742,7 @@ int items( int allow_uniques,       // not just true-false,
                                    0));
 
         // misc items placement wholly dependent upon current depth {dlb}:
-        if (item_level > 7 && (20 + item_level) >= random2(3500))
+        if (item_level > 7 && x_chance_in_y(21 + item_level, 3500))
             item.base_type = OBJ_MISCELLANY;
 
         if (item_level < 7
@@ -3045,7 +3051,7 @@ static item_make_species_type _give_weapon(monsters *mon, int level,
         }
         // intentional fallthrough
     case MONS_BIG_KOBOLD:
-        if (random2(5) < 3)     // give hand weapon
+        if (x_chance_in_y(3, 5))     // give hand weapon
         {
             item.base_type = OBJ_WEAPONS;
 
@@ -3062,7 +3068,7 @@ static item_make_species_type _give_weapon(monsters *mon, int level,
         if (one_chance_in(3))
             item_race = MAKE_ITEM_ORCISH;
 
-        if (random2(5) < 3)     // give hand weapon
+        if (x_chance_in_y(3, 5))     // give hand weapon
         {
             item.base_type = OBJ_WEAPONS;
             item.sub_type = WPN_CLUB;
@@ -3085,7 +3091,7 @@ static item_make_species_type _give_weapon(monsters *mon, int level,
         // deliberate fall through {dlb}
     case MONS_JESSICA:
     case MONS_IJYB:
-        if (random2(5) < 3)     // < 1 // give hand weapon
+        if (x_chance_in_y(3, 5))     // give hand weapon
         {
             item.base_type = OBJ_WEAPONS;
             item.sub_type = (coinflip() ? WPN_DAGGER : WPN_CLUB);
@@ -3641,7 +3647,7 @@ static item_make_species_type _give_weapon(monsters *mon, int level,
 
     if (!force_item && mons_is_unique( mon->type ))
     {
-        if (random2(100) <= 9 + mon->hit_dice)
+        if (x_chance_in_y(10 + mon->hit_dice, 100))
             level = MAKE_GOOD_ITEM;
         else if (level != MAKE_GOOD_ITEM)
             level += 5;
@@ -3719,7 +3725,7 @@ static void _give_ammo(monsters *mon, int level,
         {
         case MONS_KOBOLD:
         case MONS_BIG_KOBOLD:
-            if (random2(5) < 2)
+            if (x_chance_in_y(2, 5))
             {
                 item_race = MAKE_ITEM_NO_RACE;
                 weap_class = OBJ_MISSILES;
@@ -3949,7 +3955,7 @@ void give_armour(monsters *mon, int level)
     case MONS_NORBERT:
     case MONS_PSYCHE:
     case MONS_TERENCE:
-        if (random2(5) < 2)
+        if (x_chance_in_y(2, 5))
         {
             mitm[bp].base_type = OBJ_ARMOUR;
 
@@ -4113,7 +4119,7 @@ void give_armour(monsters *mon, int level)
 
     if (mons_is_unique( mon->type ) && level != MAKE_GOOD_ITEM)
     {
-        if (random2(100) < 9 + mon->hit_dice)
+        if (x_chance_in_y(9 + mon->hit_dice, 100))
             level = MAKE_GOOD_ITEM;
         else
             level = level * 2 + 5;
@@ -4189,22 +4195,22 @@ armour_type get_random_armour_type(int item_level)
 {
     int armtype = random2(3);
 
-    if (random2(35) <= item_level + 10)
+    if (x_chance_in_y(11 + item_level, 35))
     {
         armtype = random2(5);
         if (one_chance_in(4))
             armtype = ARM_ANIMAL_SKIN;
     }
 
-    if (random2(60) <= item_level + 10)
+    if (x_chance_in_y(11 + item_level, 60))
         armtype = random2(ARM_SHIELD); // body armour of some kind
 
-    if (10 + item_level >= random2(400) && one_chance_in(20))
+    if (one_chance_in(20) && x_chance_in_y(11 + item_level, 400))
         armtype = ARM_DRAGON_HIDE + random2(7); // (ice) dragon/troll/crystal
 
-    if (10 + item_level >= random2(500) && one_chance_in(20))
+    if (one_chance_in(20) && x_chance_in_y(11 + item_level, 500))
     {
-        // other dragon hides/armour or animal skin
+        // Other dragon hides/armour or animal skin.
         armtype = ARM_STEAM_DRAGON_HIDE + random2(11);
 
         if (armtype == ARM_ANIMAL_SKIN && one_chance_in(20))
diff --git a/crawl-ref/source/mapdef.cc b/crawl-ref/source/mapdef.cc
index 851c9819fe..362bd33c11 100644
--- a/crawl-ref/source/mapdef.cc
+++ b/crawl-ref/source/mapdef.cc
@@ -1835,7 +1835,7 @@ mons_spec mons_list::pick_monster(mons_spec_slot &slot)
          i != slot.mlist.end(); ++i)
     {
         const int weight = i->genweight;
-        if (random2(totweight += weight) < weight)
+        if (x_chance_in_y(weight, totweight += weight))
         {
             pick = *i;
 
@@ -2266,7 +2266,7 @@ item_spec item_list::pick_item(item_spec_slot &slot)
          i != slot.ilist.end(); ++i)
     {
         const int weight = i->genweight;
-        if (random2(cumulative += weight) < weight)
+        if (x_chance_in_y(weight, cumulative += weight))
             spec = *i;
     }
 
@@ -2673,10 +2673,8 @@ int subst_spec::value()
     int cumulative = 0;
     int chosen = 0;
     for (int i = 0, size = repl.size(); i < size; ++i)
-    {
-        if (random2(cumulative += repl[i].second) < repl[i].second)
+        if (x_chance_in_y(repl[i].second, cumulative += repl[i].second))
             chosen = repl[i].first;
-    }
 
     if (fix)
         frozen_value = chosen;
@@ -2767,7 +2765,7 @@ int colour_spec::get_colour()
     int chosen = BLACK;
     int cweight = 0;
     for (int i = 0, size = colours.size(); i < size; ++i)
-        if (random2(cweight += colours[i].second) < colours[i].second)
+        if (x_chance_in_y(colours[i].second, cweight += colours[i].second))
             chosen = colours[i].first;
     if (fix)
         fixed_colour = chosen;
@@ -3079,7 +3077,7 @@ feature_spec feature_slot::get_feat(int def_glyph)
     for (int i = 0, size = feats.size(); i < size; ++i)
     {
         const feature_spec &feat = feats[i];
-        if (random2(tweight += feat.genweight) < feat.genweight)
+        if (x_chance_in_y(feat.genweight, tweight += feat.genweight))
             chosen_feat = feat;
     }
 
diff --git a/crawl-ref/source/misc.cc b/crawl-ref/source/misc.cc
index 14f1e568d5..aa560a50d4 100644
--- a/crawl-ref/source/misc.cc
+++ b/crawl-ref/source/misc.cc
@@ -1125,7 +1125,7 @@ static void maybe_bloodify_square(int x, int y, int amount, bool spatter = false
     if (!spatter && !allow_bleeding_on_square(x,y))
         return;
 
-    if (amount > random2(20))
+    if (x_chance_in_y(amount, 20))
     {
 #ifdef DEBUG_DIAGNOSTICS
         mprf(MSGCH_DIAGNOSTICS,
@@ -1269,14 +1269,14 @@ void search_around( bool only_adjacent )
                 int effective = you.skills[SK_TRAPS_DOORS] / (2*dist - 1);
 
                 if (grd[srx][sry] == DNGN_SECRET_DOOR
-                    && random2(17) <= effective)
+                    && x_chance_in_y(effective + 1, 17))
                 {
                     mpr("You found a secret door!");
                     reveal_secret_door(srx, sry);
                     exercise(SK_TRAPS_DOORS, (coinflip() ? 2 : 1));
                 }
                 else if (grd[srx][sry] == DNGN_UNDISCOVERED_TRAP
-                         && random2(17) <= effective)
+                         && x_chance_in_y(effective + 1, 17))
                 {
                     i = trap_at_xy(srx, sry);
 
diff --git a/crawl-ref/source/mon-util.cc b/crawl-ref/source/mon-util.cc
index 94a0ffbc2f..ba81b53e8a 100644
--- a/crawl-ref/source/mon-util.cc
+++ b/crawl-ref/source/mon-util.cc
@@ -5689,7 +5689,7 @@ void monsters::apply_enchantment(const mon_enchant &me)
             int damage = 0;
 
             // tiny: 1/6, little: 2/5, small: 3/4, medium and above: always
-            if (random2(SIZE_GIANT - mon_size) <= mon_size)
+            if (x_chance_in_y(mon_size + 1, SIZE_GIANT - mon_size))
                 damage++;
 
             // Handled specially to make up for its small size.
@@ -5895,7 +5895,7 @@ void monsters::apply_enchantment(const mon_enchant &me)
 
     case ENCH_SHAPESHIFTER:     // This ench never runs out!
         if (type == MONS_SHAPESHIFTER
-            || random2(1000) < ( 1000 / ((15 * hit_dice) / 5)))
+            || x_chance_in_y(1000 / (15 * hit_dice / 5), 1000))
         {
             monster_polymorph(this, RANDOM_MONSTER, PPT_SAME);
         }
@@ -6381,7 +6381,7 @@ void monsters::react_to_damage(int damage)
 {
     // The royal jelly objects to taking damage and will SULK. :-)
     if (type == MONS_ROYAL_JELLY && alive()
-        && damage > 8 && random2(50) < damage)
+        && damage > 8 && x_chance_in_y(damage, 50))
     {
         const int tospawn =
             1 + random2avg(1 + std::min((damage - 8) / 8, 5), 2);
diff --git a/crawl-ref/source/monstuff.cc b/crawl-ref/source/monstuff.cc
index 920f4d528e..643e0b2d37 100644
--- a/crawl-ref/source/monstuff.cc
+++ b/crawl-ref/source/monstuff.cc
@@ -2266,7 +2266,7 @@ static bool _choose_random_patrol_target_grid(monsters *mon)
             {
                 // Slightly greater chance to simply head for the centre.
                 count_grids += 3;
-                if (random2(count_grids) < 3)
+                if (x_chance_in_y(3, count_grids))
                     set_target = true;
             }
             else if (one_chance_in(++count_grids))
@@ -3538,7 +3538,7 @@ monsters *choose_random_monster_on_level(int weight,
                     {
                         mons_count += 2;
                         // Named monsters have doubled chances.
-                        if (random2(mons_count) < 2)
+                        if (x_chance_in_y(2, mons_count))
                             chosen = mon;
                     }
                     else if (one_chance_in(++mons_count))
@@ -4233,7 +4233,7 @@ static bool _handle_special_ability(monsters *monster, bolt & beem)
         if (!mons_player_visible( monster ))
             break;
 
-        if (monster->type != MONS_HELL_HOUND && random2(13) < 3
+        if (monster->type != MONS_HELL_HOUND && x_chance_in_y(3, 13)
             || one_chance_in(10))
         {
             setup_dragon(monster, beem);
@@ -5624,7 +5624,7 @@ int mons_natural_regen_rate(monsters *monster)
 static inline bool _mons_natural_regen_roll(monsters *monster)
 {
     const int regen_rate = mons_natural_regen_rate(monster);
-    return (random2(25) < regen_rate);
+    return (x_chance_in_y(regen_rate, 25));
 }
 
 // Do natural regeneration for monster.
@@ -5996,7 +5996,7 @@ static void _handle_monster_move(int i, monsters *monster)
                         }
                     }
 
-                if (random2(2 + pfound) < 2)
+                if (x_chance_in_y(2, 2 + pfound))
                     mmov_x = mmov_y = 0;
 
                 // Bounds check: don't let confused monsters try to run
@@ -7030,7 +7030,7 @@ static bool _mon_can_move_to_pos(const monsters *monster, const int count_x,
         case CLOUD_STINK:
             if (mons_res_poison(monster) > 0)
                 return (true);
-            if (1 + random2(5) < monster->hit_dice)
+            if (x_chance_in_y(monster->hit_dice - 1, 5))
                 return (true);
             if (monster->hit_points >= random2avg(19, 2))
                 return (true);
diff --git a/crawl-ref/source/ouch.cc b/crawl-ref/source/ouch.cc
index e60da7c57b..79ba0944ee 100644
--- a/crawl-ref/source/ouch.cc
+++ b/crawl-ref/source/ouch.cc
@@ -277,7 +277,7 @@ void splash_with_acid( char acid_strength )
             continue;
         }
 
-        if (random2(20) <= acid_strength)
+        if (x_chance_in_y(acid_strength + 1, 20))
             item_corrode( you.equip[splc] );
     }
 
@@ -309,11 +309,10 @@ void weapon_acid( char acid_strength )
         msg::stream << "Your " << your_hand(true) << " burn!" << std::endl;
         ouch( roll_dice( 1, acid_strength ), 0, KILLED_BY_ACID );
     }
-    else if (random2(20) <= acid_strength)
-    {
+
+    if (x_chance_in_y(acid_strength + 1, 20))
         item_corrode( hand_thing );
-    }
-}                               // end weapon_acid()
+}
 
 void item_corrode( int itco )
 {
diff --git a/crawl-ref/source/player.cc b/crawl-ref/source/player.cc
index 15cb592619..aa308bf8d5 100644
--- a/crawl-ref/source/player.cc
+++ b/crawl-ref/source/player.cc
@@ -2852,7 +2852,7 @@ void forget_map(unsigned char chance_forgotten, bool force)
         for (unsigned char ycount = 0; ycount < GYM; ycount++)
         {
             if (!see_grid(xcount, ycount)
-                && (force || random2(100) < chance_forgotten))
+                && (force || x_chance_in_y(chance_forgotten, 100)))
             {
                 env.map[xcount][ycount].clear();
             }
@@ -6733,7 +6733,7 @@ void player::awake()
 
 void player::check_awaken(int disturbance)
 {
-    if (asleep() && random2(50) <= disturbance)
+    if (asleep() && x_chance_in_y(disturbance + 1, 50))
         awake();
 }
 
diff --git a/crawl-ref/source/randart.cc b/crawl-ref/source/randart.cc
index 8d35c5f481..e0108b9d80 100644
--- a/crawl-ref/source/randart.cc
+++ b/crawl-ref/source/randart.cc
@@ -829,7 +829,11 @@ void static _get_randart_properties(const item_def &item,
         }
     }
 
-    bool done_powers = (random2(12 < power_level));
+    // This can't be right. random2(boolean) == 0, always. (jpeg)
+//    bool done_powers = (random2(12 < power_level));
+
+   // Try to improve items that still have a low power level.
+   bool done_powers = x_chance_in_y(power_level, 12);
 
     // res_fire
     if (!done_powers
diff --git a/crawl-ref/source/religion.cc b/crawl-ref/source/religion.cc
index 5685844599..6835875cf9 100644
--- a/crawl-ref/source/religion.cc
+++ b/crawl-ref/source/religion.cc
@@ -999,8 +999,8 @@ static void _give_nemelex_gift()
 
     // Nemelex will give at least one gift early.
     if (you.num_gifts[GOD_NEMELEX_XOBEH] == 0
-           && random2(piety_breakpoint(1)) <= you.piety
-        || random2(MAX_PIETY) <= you.piety && one_chance_in(3)
+           && x_chance_in_y(you.piety + 1, piety_breakpoint(1))
+        || x_chance_in_y(you.piety + 1, MAX_PIETY) && one_chance_in(3)
            && !you.attribute[ATTR_CARD_COUNTDOWN])
     {
         misc_item_type gift_type;
@@ -1208,7 +1208,7 @@ static bool _blessing_healing(monsters* mon, bool extra)
     if (heal_monster(mon, mon->max_hit_points, extra))
     {
         // A high-HP monster might get a unique name.
-        if (random2(100) <= mon->max_hit_points)
+        if (x_chance_in_y(mon->max_hit_points + 1, 100))
             give_monster_proper_name(mon);
         return (true);
     }
@@ -3600,7 +3600,7 @@ static void _ely_dull_inventory_weapons()
 
     if (num_dulled > 0)
     {
-        if (chance >= random2(100))
+        if (x_chance_in_y(chance + 1, 100))
             dec_penance(GOD_ELYVILON, 1);
 
         simple_god_message(
@@ -5200,7 +5200,7 @@ static piety_gain_t _sacrifice_one_item_noncount( const item_def& item)
     switch (you.religion)
     {
     case GOD_NEMELEX_XOBEH:
-        if (you.attribute[ATTR_CARD_COUNTDOWN] && random2(800) < value)
+        if (you.attribute[ATTR_CARD_COUNTDOWN] && x_chance_in_y(value, 800))
         {
             you.attribute[ATTR_CARD_COUNTDOWN]--;
 #if DEBUG_DIAGNOSTICS || DEBUG_CARDS || DEBUG_SACRIFICE
@@ -5211,7 +5211,7 @@ static piety_gain_t _sacrifice_one_item_noncount( const item_def& item)
         if (item.base_type == OBJ_CORPSES && one_chance_in(2+you.piety/50)
             // Nemelex piety gain is fairly fast...at least
             // when you have low piety.
-            || value/2 >= random2(30 + you.piety/2))
+            || x_chance_in_y(value/2 + 1, 30 + you.piety/2))
         {
             if ( is_artefact(item) )
             {
@@ -5241,27 +5241,6 @@ static piety_gain_t _sacrifice_one_item_noncount( const item_def& item)
             you.sacrifice_value[item.base_type] += value;
         break;
 
-    case GOD_OKAWARU:
-    case GOD_MAKHLEB:
-        if (item.base_type == OBJ_CORPSES
-            || value >= random2(200)
-            || (player_under_penance() && value >= random2(5)))
-        {
-            gain_piety(1);
-            relative_piety_gain = PIETY_SOME;
-        }
-        break;
-
-    case GOD_SIF_MUNA:
-        if (value >= 150)       // no point in saccing stacks to Sif
-        {
-            gain_piety(1 + random2(3));
-            relative_piety_gain = PIETY_SOME;
-        }
-        break;
-
-    case GOD_KIKUBAAQUDGHA:
-    case GOD_TROG:
     case GOD_SHINING_ONE:
         gain_piety(1);
         relative_piety_gain = PIETY_SOME;
@@ -5270,7 +5249,7 @@ static piety_gain_t _sacrifice_one_item_noncount( const item_def& item)
     default:
         break;
     }
-    return relative_piety_gain;
+    return (relative_piety_gain);
 }
 
 void offer_items()
@@ -5670,7 +5649,7 @@ harm_protection_type god_protects_from_harm(god_type god, bool actual)
     const int min_piety = piety_breakpoint(0);
     bool praying = (you.duration[DUR_PRAYER]
                     && random2(you.piety) >= min_piety);
-    bool anytime = (one_chance_in(10) || you.piety > random2(1000));
+    bool anytime = (one_chance_in(10) || x_chance_in_y(you.piety, 1000));
     bool penance = you.penance[god];
 
     // If actual is true, return HPT_NONE if the given god can protect
@@ -5712,8 +5691,8 @@ void god_smites_you(god_type god, kill_method_type death_type,
 {
     // Your god won't protect you from his own smiting, and Xom is too
     // capricious to protect you from any god's smiting.
-    if (you.religion != god && you.religion != GOD_XOM &&
-        !player_under_penance() && you.piety > random2(MAX_PIETY * 2))
+    if (you.religion != god && you.religion != GOD_XOM
+        && !player_under_penance() && x_chance_in_y(you.piety, MAX_PIETY * 2))
     {
         god_speaks(you.religion,
                    make_stringf("Mortal, I have averted the wrath of %s... "
@@ -5820,7 +5799,7 @@ void handle_god_time()
             const char *origfavour = describe_xom_favour();
             const bool good = you.piety > (MAX_PIETY / 2);
             int size = abs(you.piety - 100);
-            delta = (random2(1000) < 511) ? 1 : -1;
+            delta = (x_chance_in_y(511, 1000) ? 1 : -1);
             size += delta;
             you.piety = (MAX_PIETY / 2) + (good ? size : -size);
             const char *newfavour = describe_xom_favour();
diff --git a/crawl-ref/source/spells4.cc b/crawl-ref/source/spells4.cc
index 5d62772b28..3acf2fe0b4 100644
--- a/crawl-ref/source/spells4.cc
+++ b/crawl-ref/source/spells4.cc
@@ -1976,7 +1976,7 @@ void cast_fragmentation(int pow)        // jmf: ripped idea from airstrike
         blast.name       = "blast of metal fragments";
         blast.damage.num = 4;
 
-        if (okay_to_dest && pow >= 80 && random2(500) < pow / 5)
+        if (okay_to_dest && pow >= 80 && x_chance_in_y(pow / 5, 500))
         {
             blast.damage.num += 2;
             grd[beam.tx][beam.ty] = DNGN_FLOOR;
diff --git a/crawl-ref/source/spl-book.cc b/crawl-ref/source/spl-book.cc
index 9192e4dd4e..0ab544910f 100644
--- a/crawl-ref/source/spl-book.cc
+++ b/crawl-ref/source/spl-book.cc
@@ -1311,7 +1311,7 @@ bool learn_spell(int book)
     }
 
     if (player_mutation_level(MUT_BLURRY_VISION) > 0
-        && random2(4) < player_mutation_level(MUT_BLURRY_VISION))
+        && x_chance_in_y(player_mutation_level(MUT_BLURRY_VISION), 4))
     {
         mpr("The writing blurs into unreadable gibberish.");
         you.turn_is_over = true;
diff --git a/crawl-ref/source/spl-cast.cc b/crawl-ref/source/spl-cast.cc
index 08e9890a99..51a3c0ff70 100644
--- a/crawl-ref/source/spl-cast.cc
+++ b/crawl-ref/source/spl-cast.cc
@@ -1100,10 +1100,10 @@ spret_type your_spells(spell_type spell, int powc, bool allow_fail)
 
             if (you.religion == GOD_SIF_MUNA
                 && !player_under_penance()
-                && you.piety >= 100 && random2(150) <= you.piety)
+                && you.piety >= 100 && x_chance_in_y(you.piety + 1, 150))
             {
                 canned_msg(MSG_NOTHING_HAPPENS);
-                return SPRET_FAIL;
+                return (SPRET_FAIL);
             }
 
             unsigned int sptype = 0;
@@ -2896,8 +2896,8 @@ static void _miscast_divination(int severity, const char* cause)
 static void _miscast_necromancy(int severity, const char* cause)
 {
     if (you.religion == GOD_KIKUBAAQUDGHA
-        && (!player_under_penance() && you.piety >= piety_breakpoint(1)
-            && you.piety > random2(150)))
+        && !player_under_penance() && you.piety >= piety_breakpoint(1)
+        && x_chance_in_y(you.piety, 150))
     {
         canned_msg(MSG_NOTHING_HAPPENS);
         return;
diff --git a/crawl-ref/source/traps.cc b/crawl-ref/source/traps.cc
index 5822d624f3..0b726a678f 100644
--- a/crawl-ref/source/traps.cc
+++ b/crawl-ref/source/traps.cc
@@ -254,7 +254,7 @@ static void dart_trap(bool trap_known, int trapped, bolt &pbolt, bool poison)
             msg += "hits you!";
             mpr(msg.c_str());
 
-            if (poison && random2(100) < 50 - (3 * player_AC()) / 2
+            if (poison && x_chance_in_y(50 - (3 * player_AC()) / 2, 100)
                 && !player_res_poison())
             {
                 poison_player( 1 + random2(3) );
@@ -721,27 +721,27 @@ static int damage_or_escape_net(int hold)
             damage += level - 1;
     }
 
-    // Berserkers get a fighting bonus
+    // Berserkers get a fighting bonus.
     if (you.duration[DUR_BERSERKER])
         damage += 2;
 
-    // check stats
-    if (you.strength > random2(18))
+    // Check stats.
+    if (x_chance_in_y(you.strength, 18))
         damage++;
-    if (you.dex > random2(12))
+    if (x_chance_in_y(you.dex, 12))
         escape++;
-    if (player_evasion() > random2(20))
+    if (x_chance_in_y(player_evasion(), 20))
         escape++;
 
-    // monsters around you add urgency
+    // Monsters around you add urgency.
     if (!i_feel_safe())
     {
         damage++;
         escape++;
     }
 
-    // confusion makes the whole thing somewhat harder
-    // (less so for trying to escape)
+    // Confusion makes the whole thing somewhat harder
+    // (less so for trying to escape).
     if (you.duration[DUR_CONF])
     {
         if (escape > 1)
@@ -750,26 +750,26 @@ static int damage_or_escape_net(int hold)
             damage -= 2;
     }
 
-    // damaged nets are easier to destroy
+    // Damaged nets are easier to destroy.
     if (hold < 0)
     {
         damage += random2(-hold/3 + 1);
 
-        // ... and easier to slip out of (but only if escape looks feasible)
+        // ... and easier to slip out of (but only if escape looks feasible).
         if (you.attribute[ATTR_HELD] < 5 || escape >= damage)
             escape += random2(-hold/2) + 1;
     }
 
-    // if undecided, choose damaging approach (it's quicker)
+    // If undecided, choose damaging approach (it's quicker).
     if (damage >= escape)
         return (-damage); // negate value
 
     return (escape);
 }
 
-// calls the above function to decide on how to get free
-// note that usually the net will be damaged until trying to slip out
-// becomes feasible (for size etc.), so it may take even longer
+// Calls the above function to decide on how to get free.
+// Note that usually the net will be damaged until trying to slip out
+// becomes feasible (for size etc.), so it may take even longer.
 void free_self_from_net()
 {
     int net = get_trapping_net(you.x_pos, you.y_pos);
@@ -787,9 +787,10 @@ void free_self_from_net()
          hold, you.attribute[ATTR_HELD], do_what);
 #endif
 
-    if (do_what <= 0) // you try to destroy the net
-    {                 // for previously undamaged nets this takes at least 2
-                      // and at most 8 turns
+    if (do_what <= 0) // You try to destroy the net
+    {
+        // For previously undamaged nets this takes at least 2 and at most
+        // 8 turns.
         bool can_slice = you.attribute[ATTR_TRANSFORMATION] == TRAN_BLADE_HANDS
                          || you.equip[EQ_WEAPON] != -1
                             && can_cut_meat(you.inv[you.equip[EQ_WEAPON]]);
@@ -802,7 +803,8 @@ void free_self_from_net()
         if (you.duration[DUR_BERSERKER])
             damage *= 2;
 
-        // medium sized characters are at disadvantage and sometimes get a bonus
+        // Medium sized characters are at disadvantage and sometimes
+        // get a bonus.
         if (you.body_size(PSIZE_BODY) == SIZE_MEDIUM)
             damage += coinflip();
 
@@ -832,8 +834,8 @@ void free_self_from_net()
         else
             mpr("You struggle against the net.");
 
-        // occasionally decrease duration a bit
-        // (this is so switching from damage to escape does not hurt as much)
+        // Occasionally decrease duration a bit
+        // (this is so switching from damage to escape does not hurt as much).
         if (you.attribute[ATTR_HELD] > 1 && coinflip())
         {
             you.attribute[ATTR_HELD]--;
@@ -842,14 +844,16 @@ void free_self_from_net()
                 you.attribute[ATTR_HELD]--;
         }
    }
-   else // you try to escape (takes at least 3 turns, and at most 10)
+   else
    {
+        // You try to escape (takes at least 3 turns, and at most 10).
         int escape = do_what;
 
         if (you.duration[DUR_HASTE]) // extra bonus, also Berserk
             escape++;
 
-        // medium sized characters are at disadvantage and sometimes get a bonus
+        // Medium sized characters are at disadvantage and sometimes
+        // get a bonus.
         if (you.body_size(PSIZE_BODY) == SIZE_MEDIUM)
             escape += coinflip();
 
diff --git a/crawl-ref/source/view.cc b/crawl-ref/source/view.cc
index 89cc37c67c..c25c8d874f 100644
--- a/crawl-ref/source/view.cc
+++ b/crawl-ref/source/view.cc
@@ -804,7 +804,7 @@ static void _good_god_follower_attitude_change(monsters *monster)
     {
         monster->flags |= MF_ATT_CHANGE_ATTEMPT;
 
-        if (you.piety > random2(MAX_PIETY) && !you.penance[you.religion])
+        if (x_chance_in_y(you.piety, MAX_PIETY) && !you.penance[you.religion])
         {
             int wpn = you.equip[EQ_WEAPON];
             if (wpn != -1
@@ -887,8 +887,11 @@ static void _handle_seen_interrupt(monsters* monster)
 
 void handle_monster_shouts(monsters* monster, bool force)
 {
-    if (!force && (!you.turn_is_over || random2(30) < you.skills[SK_STEALTH]))
+    if (!force && (!you.turn_is_over
+                   || x_chance_in_y(you.skills[SK_STEALTH], 30)))
+    {
         return;
+    }
 
     // Friendly or neutral monsters don't shout.
     if (!force && (mons_friendly(monster) || mons_neutral(monster)))
@@ -1274,7 +1277,7 @@ bool check_awaken(monsters* monster)
     if (mons_perc < 0)
         mons_perc = 0;
 
-    if (random2(stealth) <= mons_perc)
+    if (x_chance_in_y(mons_perc + 1, stealth))
         return (true); // Oops, the monster wakes up!
 
     // You didn't wake the monster!
diff --git a/crawl-ref/source/xom.cc b/crawl-ref/source/xom.cc
index 9bd707eb26..e67afa4598 100644
--- a/crawl-ref/source/xom.cc
+++ b/crawl-ref/source/xom.cc
@@ -432,7 +432,7 @@ static bool _xom_is_good(int sever)
     // This series of random calls produces a poisson-looking
     // distribution: initial hump, plus a long-ish tail.
 
-    if (random2(sever) <= 1)
+    if (x_chance_in_y(2, sever))
     {
         potion_type pot =
             static_cast<potion_type>(
@@ -456,13 +456,13 @@ static bool _xom_is_good(int sever)
             done = true;
         }
     }
-    else if (random2(sever) <= 2)
+    else if (x_chance_in_y(3, sever))
     {
         _xom_makes_you_cast_random_spell(sever);
 
         done = true;
     }
-    else if (random2(sever) <= 3)
+    else if (x_chance_in_y(4, sever))
     {
         // XXX: Can we clean up this ugliness, please?
         const int numdemons =
@@ -544,13 +544,13 @@ static bool _xom_is_good(int sever)
         delete[] is_demonic;
         delete[] summons;
     }
-    else if (random2(sever) <= 4)
+    else if (x_chance_in_y(5, sever))
     {
         _xom_gives_item(sever);
 
         done = true;
     }
-    else if (random2(sever) <= 5)
+    else if (x_chance_in_y(6, sever))
     {
         monster_type mon = _xom_random_demon(sever);
         const bool is_demonic = (mons_class_holiness(mon) == MH_DEMONIC);
@@ -586,7 +586,7 @@ static bool _xom_is_good(int sever)
             done = true;
         }
     }
-    else if (random2(sever) <= 6)
+    else if (x_chance_in_y(7, sever))
     {
         if (there_are_monsters_nearby())
         {
@@ -614,13 +614,13 @@ static bool _xom_is_good(int sever)
             }
         }
     }
-    else if (random2(sever) <= 7)
+    else if (x_chance_in_y(8, sever))
     {
         _xom_gives_item(sever);
 
         done = true;
     }
-    else if (random2(sever) <= 8)
+    else if (x_chance_in_y(9, sever))
     {
         // This can fail with radius 1, or in open areas.
         if (vitrify_area(random2avg(sever / 2, 3) + 1))
@@ -630,7 +630,7 @@ static bool _xom_is_good(int sever)
             done = true;
         }
     }
-    else if (random2(sever) <= 9)
+    else if (x_chance_in_y(10, sever))
     {
         if (you.can_safely_mutate()
             && player_mutation_level(MUT_MUTATION_RESISTANCE) < 3)
@@ -653,7 +653,7 @@ static bool _xom_is_good(int sever)
             }
         }
     }
-    else if (random2(sever) <= 10)
+    else if (x_chance_in_y(11, sever))
     {
         monster_type mon = _xom_random_demon(sever);
         const bool is_demonic = (mons_class_holiness(mon) == MH_DEMONIC);
@@ -689,7 +689,7 @@ static bool _xom_is_good(int sever)
             done = true;
         }
     }
-    else if (random2(sever) <= 11)
+    else if (x_chance_in_y(12, sever))
     {
         if (player_in_a_dangerous_place())
         {
@@ -735,7 +735,7 @@ static bool _xom_is_bad(int sever)
 
     while (!done)
     {
-        if (random2(sever) <= 2)
+        if (x_chance_in_y(3, sever))
         {
             god_speaks(GOD_XOM, _get_xom_speech("zero miscast effect").c_str());
 
@@ -743,7 +743,7 @@ static bool _xom_is_bad(int sever)
 
             done = true;
         }
-        else if (random2(sever) <= 3)
+        else if (x_chance_in_y(4, sever))
         {
             god_speaks(GOD_XOM, _get_xom_speech("minor miscast effect").c_str());
 
@@ -752,7 +752,7 @@ static bool _xom_is_bad(int sever)
 
             done = true;
         }
-        else if (random2(sever) <= 4)
+        else if (x_chance_in_y(5, sever))
         {
             god_speaks(GOD_XOM, _get_xom_speech("lose stats").c_str());
 
@@ -761,7 +761,7 @@ static bool _xom_is_bad(int sever)
 
             done = true;
         }
-        else if (random2(sever) <= 5)
+        else if (x_chance_in_y(6, sever))
         {
             god_speaks(GOD_XOM, _get_xom_speech("medium miscast effect").c_str());
 
@@ -770,7 +770,7 @@ static bool _xom_is_bad(int sever)
 
             done = true;
         }
-        else if (random2(sever) <= 6)
+        else if (x_chance_in_y(7, sever))
         {
             if (you.can_safely_mutate()
                 && player_mutation_level(MUT_MUTATION_RESISTANCE) < 3)
@@ -793,7 +793,7 @@ static bool _xom_is_bad(int sever)
                 }
             }
         }
-        else if (random2(sever) <= 7)
+        else if (x_chance_in_y(8, sever))
         {
             if (there_are_monsters_nearby())
             {
@@ -821,7 +821,7 @@ static bool _xom_is_bad(int sever)
                 }
             }
         }
-        else if (random2(sever) <= 8)
+        else if (x_chance_in_y(9, sever))
         {
             std::string speech = _get_xom_speech("draining or torment");
 
@@ -852,7 +852,7 @@ static bool _xom_is_bad(int sever)
                 }
             }
         }
-        else if (random2(sever) <= 9)
+        else if (x_chance_in_y(10, sever))
         {
             std::string speech = _get_xom_speech("hostile monster");
 
@@ -892,7 +892,7 @@ static bool _xom_is_bad(int sever)
                 }
             }
         }
-        else if (random2(sever) <= 10)
+        else if (x_chance_in_y(11, sever))
         {
             god_speaks(GOD_XOM, _get_xom_speech("major miscast effect").c_str());