A magical barrier of acid blocks your path. Solve the puzzle to unlock the door.

A combination lock, possibly to open a chest or door or other entry point. A magical puzzle, for those interested.

Checkerboards on floors of dungeons... is there any greater bane to adventurers?

If the adventurers are smart, they can solve this riddle and get the information they need.

To be used for the final encounter, find the final treasure, or anything that needs to be hidden away better then normal. Typical 'who the heck would ever spend the time making it' but it is fun and a mental challenge for a change.

Then suddenly all your body paralizes and you hear a voice echoing in the distance "seems like another rat has been lured to my maze," this voice was terribly cold but playfull, "come on you are not already planning on leaving, the fun has only begun."