When a vault guard was created it was producing a "guard appears" message, then the vault code immediately produced a "vault's guard enters" message. Suppress the creation message. While testing that, I noticed that if the hero was blind and lacked telepathy, "someone enters" started the guard interrogation sequence but if hero answered and dropped gold, the way out wasn't discernable. Put a "remembered, unseen monster" glyph at the guard's spot in the breeched vault wall. The player will need to do <search><move> over and over to actually follow the guard but at least will know where to start doing that.
125 KiB
125 KiB