Dart and arrow traps should shoot a consistent type of dart or arrow (i.e. not shooting a +1 dart and then a +0 silver dart), and if there is a stack of them pregenerated on the trap those should be consistent with it too.

Make arrow traps multishoot arrows at higher level difficulties.

Dart and arrow traps are much more likely to generate if the trap is next to a wall. Alternatively, when generating a dart or arrow trap, look for a wall tile in line within 3 squares that contains the launching mechanism; if no such tile exists, the trap cannot generate. The player must then untrap the wall square, or dig it out, to remove the trap.

Merge dart and arrow traps into “missile” traps, that fire a random sort of missile. Also, make such traps store their ammo in the trap to be fired one by one or released when untrapped, not to be created one by one when triggering, as described in #768.