My game is an RPG that uses hand-designed maps (not randomly generated).
See
http://darkfire-rpg.comMonster generation is random however, using the following mechanism:
Invisible generators are placed on the maps (via map editor). Each generator has a list of monsters that may be randomly generated. There is also a defined range around the generator where monsters may be placed. There is a timer that will determine when to generate monsters and a cap on the number of monsters to be generated at the same time.
The described mechanic is totally simple, yet does allow for a lot of variety and flexibility.