Shaft trap behavior modified. They now are one-time use and pre-knowledge of shaft traps (i.e. using them intentionally) will improve the chances of the player landing fewer levels away. Shaft traps also now randomly determine their destination. Monsters cannot follow the player through shaft traps.

Signed-off-by: David Ploog <dploog@users.sourceforge.net>

1 files changed, 36 insertions, 50 deletions

diff --git a/crawl-ref/source/traps.cc b/crawl-ref/source/traps.cc
index a8d47fa834..4251ffe78f 100644
--- a/crawl-ref/source/traps.cc
+++ b/crawl-ref/source/traps.cc
@@ -626,6 +626,9 @@ void trap_def::trigger(actor& triggerer, bool flat_footed)
         break;
 
     case TRAP_SHAFT:
+        // Unknown shafts are traps triggered by walking onto them.
+        // Known shafts are used as escape hatches
+
         // Paranoia
         if (!is_valid_shaft_level())
         {
@@ -636,48 +639,19 @@ void trap_def::trigger(actor& triggerer, bool flat_footed)
             break;
         }
 
+        // If the shaft isn't triggered, don't reveal it.
+        if (!triggerer.will_trigger_shaft() && !you_know)
+            this->hide();
+
         // Known shafts don't trigger as traps.
         if (trig_knows)
-        {
-            if (you_trigger)
-            {
-               if (triggerer.airborne())
-               {
-                   if (you.flight_mode() == FL_LEVITATE)
-                       mpr("You float over the shaft.");
-                   else
-                       mpr("You fly over the shaft.");
-               }
-               else
-                   mpr("You carefully avoid triggering the shaft.");
-            }
             break;
-        }
-
-        if (!triggerer.will_trigger_shaft())
-        {
-            if (!you_know)
-                this->hide();
-            else if (!triggerer.airborne())
-            {
-                if (you_trigger)
-                {
-                    mpr("You don't fall through the shaft.");
-                }
-                else if (m)
-                {
-                    simple_monster_message(m,
-                                           " doesn't fall through the shaft.");
-                }
-            }
-        }
 
         // Fire away!
-        {
-            const bool revealed = triggerer.do_shaft();
-            if (!revealed && !you_know)
-                this->hide();
-        }
+        triggerer.do_shaft();
+
+        // Shafts are destroyed
+        // after one use in down_stairs(), misc.cc
         break;
 
     default:
@@ -1341,10 +1315,10 @@ bool is_valid_shaft_level(const level_id &place)
     return ((branch.depth - place.depth) >= min_delta);
 }
 
-level_id generic_shaft_dest(level_pos lpos)
+level_id generic_shaft_dest(level_pos lpos, bool known = false)
 {
-    level_id  lid = lpos.id;
-    coord_def pos = lpos.pos;
+    level_id  lid   = lpos.id;
+    coord_def pos   = lpos.pos;
 
     if (lid.level_type != LEVEL_DUNGEON)
         return lid;
@@ -1352,14 +1326,26 @@ level_id generic_shaft_dest(level_pos lpos)
     int      curr_depth = lid.depth;
     Branch   &branch    = branches[lid.branch];
 
-    // 25% drop one level
-    // 50% drop two levels
-    // 25% drop three levels
-    lid.depth += 2;
-    if (pos.x % 2)
-        lid.depth--;
-    if (pos.y % 2)
-        lid.depth++;
+    // Shaft traps' behavior depends on whether it is entered intentionally.
+    // Knowingly entering one is more likely to drop you 1 level.
+    // Falling in unknowingly can drop you 1/2/3 levels with equal chance.
+
+    if (known)
+    {
+        // Chances are 5/8s for 1 level, 2/8s for 2 levels, 1/8 for 3 levels
+        int s = random2(8) + 1;
+        if (s == 1)
+            lid.depth += 3;
+        else if (s <= 3)
+            lid.depth += 2;
+        else
+            lid.depth += 1;
+    }
+    else
+    {
+        // 33.3% for 1, 2, 3
+        lid.depth += 1 + random2(3);
+    }
 
     if (lid.depth > branch.depth)
         lid.depth = branch.depth;
@@ -1382,7 +1368,7 @@ level_id generic_shaft_dest(level_pos lpos)
     return lid;
 }
 
-level_id generic_shaft_dest(coord_def pos)
+level_id generic_shaft_dest(coord_def pos, bool known = false)
 {
     return generic_shaft_dest(level_pos(level_id::current(), pos));
 }
@@ -1392,7 +1378,7 @@ void handle_items_on_shaft(const coord_def& pos, bool open_shaft)
     if (!is_valid_shaft_level())
         return;
 
-    level_id  dest = generic_shaft_dest(pos);
+    level_id dest = generic_shaft_dest(pos);
 
     if (dest == level_id::current())
         return;