Used by the routines at MONSTER112_UPDATE and VILLAIN_WANDER.

Used by the villains (VILLAIN_WANDER) and the monsters of graphics 112-127 (MONSTER112_UPDATE). Stopped by a wall, it turns a quarter left or right at random and starts a new count of up to 63 turns. Otherwise the count (the low bits of the facing byte) goes down each turn, and when its low five bits reach 0: with bit 5 of the flags clear it turns at random the same way; with it set it turns towards the knight (KNIGHT_DIRECTION, TURN_TO_KNIGHT_TABLE) and starts a count of 1-16.

Bit 5 is set only for a monster spawned in the first half of a 256-turn cycle (SPAWN_MONSTER); the villains never have it, so they wander and never chase. The counts are set from the random number's high byte and tested on only five bits, so a count of 32-63 runs out after the count less 32.