diff --git a/source/src/physics.cpp b/source/src/physics.cpp
index febd1955..06adff5e 100644
--- a/source/src/physics.cpp
+++ b/source/src/physics.cpp
@@ -178,11 +178,13 @@ bool collide(physent *d, bool spawn, float drop, float rise, int level) // level
     float hi = 127, lo = -128;
     const float eyeheight = d->eyeheight;
     const float playerheight = eyeheight + d->aboveeye;
+    const int applyclip = d->type == ENT_PLAYER ? TAGCLIP|TAGPLCLIP : TAGCLIP;
 
     if(level&1) for(int y = y1; y<=y2; y++) for(int x = x1; x<=x2; x++)     // collide with map
     {
         if(OUTBORD(x,y)) return true;
         sqr *s = S(x,y);
+        if(s->tag & applyclip) return true;  // tagged clips feel like solids
         float ceil = s->ceil;
         float floor = s->floor;
         switch(s->type)
diff --git a/source/src/world.h b/source/src/world.h
index 361cc73e..24c75f4a 100644
--- a/source/src/world.h
+++ b/source/src/world.h
@@ -32,6 +32,13 @@ enum                            // hardcoded texture numbers
     DEFAULT_CEIL
 };
 
+enum                            // stuff encoded in sqr.tag
+{
+    TAGTRIGGERMASK = 0x3F,      // room for old fashioned cube 1 triggers
+    TAGCLIP = 0x40,             // clips all objects
+    TAGPLCLIP = 0x80            // clips only players
+};
+
 #define MAXMAPVERSION 10        // defines the highest readable format
 #define MAPVERSION 9            // default map format version to be written (bump if map format changes, see worldio.cpp)