Keeping with the logic puzzles idea....how about a game of Mastermind?
DM:
You see a stone rack. On the rack are 7 stones, all the same size but with different symbols carved on them, each is also a different color/stone. Behind them is a stone pedestal with four holes in the top. It looks like the stones have been cut to fit in the holes. The huge iron doors have 4 large eyes in them, which appear to be made of glass. (The whole contruction radiates magic, if checked.)
Player:
What the? I pick up four stones and put them in the slots.
DM: (hands out seven tokens corresponding to the stones)
Show me which ones in which hole...the holes are in a row.
Player:
Fine. This one...this one...like this.
DM:
The leftmost of the glass eyes glows white, and the third glows red. There is also a rumbling sound. The door behind you is replaced with an iron wall. Also, the ceiling appears to have lowered by a foot or so. You figure you might have 11 tries left.
Players:
!