Hand-pick Zot trap effects.

Previously Zot traps functioned by picking a random spell school and then
using a severity 3 miscast for that school. Now they draw from a hand-picked
list of possible effects (currently still mainly consisting of miscast-like
effects)..

Separating Zot trap effects out like this makes sense because miscasts and
Zot trap effects happen in different circumstances: the former are under the
player's control to a large extent and should mainly happen in combat, while
the latter often happen with no monsters around, when the player explores
into a trap. Because of this, it makes sense that some effects would work
well for one but not the other. In addition, separating the two lets us
add new Zot trap effects without needing to associate them with a spell
school.

The list of effects added in this commit is quite rough. A few comments on
it:
* I didn't use any simple "ouch" effects, which are quite common among the
miscasts. Just doing damage to the player is boring and won't do anything
if the player is exploring. Explosions are better because they cause noise
and hit multiple squares.

* Polymorphing the player into badforms was intentionally omitted. It turns
out that near-unavoidably polymorphing players on Zot:5 into forms with rF-
and/or limited item/spell options isn't very nice.

* On general request, contamination from Zot traps is less severe now. You
can certainly still get mutated from this (or directly malmutated), but
horror stories of 6 bad mutations from one trap should be less common.

1 files changed, 242 insertions, 1 deletions

diff --git a/crawl-ref/source/spl-miscast.cc b/crawl-ref/source/spl-miscast.cc
index f411b43569..8ae7110b5a 100644
--- a/crawl-ref/source/spl-miscast.cc
+++ b/crawl-ref/source/spl-miscast.cc
@@ -379,6 +379,14 @@ void MiscastEffect::do_miscast()
     msg_ch         = MSGCH_PLAIN;
     sound_loudness = 0;
 
+    if (source == ZOT_TRAP_MISCAST)
+    {
+        _zot();
+        if (target->is_player())
+            xom_is_stimulated(150);
+        return;
+    }
+
     switch (sp_type)
     {
     case SPTYP_CONJURATION:    _conjuration(severity);    break;
@@ -735,7 +743,9 @@ bool MiscastEffect::_create_monster(monster_type what, int abj_deg,
     // simply be ignored.
     if (data.abjuration_duration != 0)
     {
-        if (you.penance[god] > 0)
+        if (what == RANDOM_MOBILE_MONSTER)
+            data.summon_type = SPELL_SHADOW_CREATURES;
+        else if (you.penance[god] > 0)
             data.summon_type = MON_SUMM_WRATH;
         else if (source == ZOT_TRAP_MISCAST)
             data.summon_type = MON_SUMM_ZOT;
@@ -2846,3 +2856,234 @@ void MiscastEffect::_do_poison(int amount)
     else
         target->poison(act_source, amount);
 }
+
+void MiscastEffect::_zot()
+{
+    bool success = false;
+    int roll;
+    switch (random2(4))
+    {
+    case 0:    // mainly explosions
+        beam.name = "explosion";
+        beam.damage = dice_def(3, 20);
+        beam.ex_size = coinflip() ? 1 : 2;
+        beam.glyph   = dchar_glyph(DCHAR_FIRED_BURST);
+        switch (random2(10))
+        {
+        case 0:
+        case 1:
+            all_msg = "There is a sudden explosion of magical energy!";
+            beam.flavour = BEAM_MISSILE;
+            beam.colour  = random_colour();
+            _explosion();
+            break;
+        case 2:
+        case 3:
+            all_msg = "There is a sudden explosion of flames!";
+            beam.flavour = BEAM_FIRE;
+            beam.colour  = RED;
+            _explosion();
+            break;
+        case 4:
+        case 5:
+            all_msg = "There is a sudden explosion of frost!";
+            beam.flavour = BEAM_COLD;
+            beam.colour  = WHITE;
+            _explosion();
+            break;
+        case 6:
+            all_msg = "There is a sudden explosion of flying shrapnel!";
+            beam.flavour = BEAM_FRAG;
+            beam.colour  = CYAN;
+            _explosion();
+            break;
+        case 7:
+            all_msg = "There is a sudden explosion of electrical discharges!";
+            beam.flavour = BEAM_ELECTRICITY;
+            beam.colour  = LIGHTBLUE;
+            _explosion();
+            break;
+        case 8:
+            if (_create_monster(MONS_BALL_LIGHTNING, 3))
+                all_msg = "A ball of electricity appears!";
+            do_msg();
+            break;
+        case 9:
+            if (_create_monster(MONS_TWISTER, 1))
+                all_msg = "A huge vortex of air appears!";
+            do_msg();
+            break;
+        }
+        break;
+    case 1:    // summons
+    reroll_1:
+        switch (random2(9))
+        {
+        case 0:
+            if (_create_monster(MONS_SOUL_EATER, 4, true))
+            {
+                you_msg        = "Something reaches out for you...";
+                mon_msg_seen   = "Something reaches out for @the_monster@...";
+                mon_msg_unseen = "Something reaches out from thin air...";
+            }
+            do_msg();
+            break;
+        case 1:
+            if (_create_monster(MONS_REAPER, 4, true))
+            {
+                you_msg        = "Death has come for you...";
+                mon_msg_seen   = "Death has come for @the_monster@...";
+                mon_msg_unseen = "Death appears from thin air...";
+            }
+            do_msg();
+            break;
+        case 2:
+            if (_create_monster(summon_any_demon(RANDOM_DEMON_GREATER), 0, true))
+                all_msg = "You sense a hostile presence.";
+            do_msg();
+            break;
+        case 3:
+        case 4:
+            for (int i = 1 + random2(2); i >= 0; --i)
+            {
+                if (_create_monster(summon_any_demon(RANDOM_DEMON_COMMON), 0, true))
+                    success = true;
+            }
+            if (success)
+            {
+                you_msg = "Something turns its malign attention towards "
+                          "you...";
+                mon_msg = "You sense a malign presence.";
+                do_msg();
+            }
+            break;
+        case 5:
+            for (int i = 3 + random2(5); i >= 0; --i)
+            {
+                if (_create_monster(summon_any_demon(RANDOM_DEMON_LESSER), 0, true))
+                    success = true;
+            }
+            if (success && neither_end_silenced())
+            {
+                you_msg        = "A chorus of chattering voices calls out to"
+                                 " you!";
+                mon_msg        = "A chorus of chattering voices calls out!";
+                msg_ch         = MSGCH_SOUND;
+                sound_loudness = 3;
+                do_msg();
+            }
+            break;
+        case 6:
+        case 7:
+            for (int i = 2 + random2(3); i >= 0; --i)
+            {
+                if (_create_monster(RANDOM_MOBILE_MONSTER, 4, true))
+                    success = true;
+            }
+            if (success)
+            {
+                all_msg = "Wisps of shadow whirl around...";
+                do_msg();
+            }
+            break;
+        case 8:
+            if (!_malign_gateway())
+                goto reroll_1;
+            break;
+        }
+        break;
+    case 2:
+    case 3:    // other misc stuff
+    reroll_2:
+        // Cases at the end are for players only.
+        switch (random2(target->is_player() ? 14 : 10))
+        {
+        case 0:
+            target->paralyse(act_source, 2 + random2(4), cause);
+            break;
+        case 1:
+            target->petrify(guilty);
+            break;
+        case 2:
+            target->rot(act_source, 0, 3 + random2(3));
+            break;
+        case 3:
+            if (!_send_to_abyss())
+                goto reroll_2;
+            break;
+        case 4:
+            you_msg      = "You feel incredibly sick.";
+            mon_msg_seen = "@The_monster@ looks incredibly sick.";
+            _do_poison(10 + random2avg(19, 2));
+            do_msg();
+            break;
+        case 5:
+            if (!target->is_player())
+                target->polymorph(0);
+            else if (coinflip())
+            {
+                you_msg = "You feel very strange.";
+                delete_mutation(RANDOM_MUTATION, cause, true, false, false, false);
+                do_msg();
+            }
+            else
+            {
+                you_msg = "Your body is distorted in a weirdly horrible way!";
+                give_bad_mutation(cause, false, false);
+                if (coinflip())
+                    give_bad_mutation(cause, false, false);
+                do_msg();
+            }
+            break;
+        case 6:
+        case 7:
+            roll = random2(3); // Give 2 of 3 effects.
+            if (roll != 0)
+                _potion_effect(POT_CONFUSION, 15);
+            if (roll != 1)
+                _potion_effect(POT_SLOWING, 15);
+            if (roll != 2)
+            {
+                you_msg        = "Space warps around you!";
+                mon_msg_seen   = "Space warps around @the_monster@!";
+                mon_msg_unseen = "A piece of empty space twists and writhes.";
+                _ouch(5 + random2avg(9, 2));
+                if (target->alive())
+                {
+                    if (!target->no_tele())
+                    {
+                        if (one_chance_in(3))
+                            target->teleport(true);
+                        else
+                            target->blink(false);
+                    }
+                }
+            }
+            break;
+        case 8:
+        case 9:
+            if (target->is_player())
+                contaminate_player(2 + random2avg(14, 2), false);
+            else
+                target->polymorph(0);
+            break;
+        case 10:
+            if (you.magic_points > 0)
+            {
+                dec_mp(10 + random2(21));
+                mpr("You suddenly feel drained of magical energy!", MSGCH_WARN);
+            }
+            break;
+        case 11:
+        case 12:
+            _lose_stat(STAT_RANDOM, 1 + random2avg((coinflip() ? 7 : 4), 2));
+            break;
+        case 13:
+            mpr("An unnatural silence engulfs you.");
+            you.increase_duration(DUR_SILENCE, 10 + random2(21), 30);
+            invalidate_agrid(true);
+            break;
+        }
+        break;
+    }
+}