“ What about a 'criminal' society with distinct laws - for stealing, the larger the value of something stolen, the less punishment the courageous thief recieves (but must return it of course). For this pirates(?) caught petty thieves deserve to be punished harshly. If you take, you better take a lot.”
“ Have a large room that elevates either up or down when triggering a trap. The floor can bring the players to new levels, where a mighty beast roams, or the floor flattens the players into the ceiling or drop into a pit of lava.”
“ A Cloak of Shadows that causes mushrooms to grow in its own shadow. A crouching theif might find himself in a ring of poisonous toadstools, an interesting thing for a sentry to find after the thief has left hiding place.”