Help with interesting puzzles to vex my players

[Fallenibilis]

As the title states im looking for some already made puzzles or ideas to help me make a few puzzles. Specificly im looking for a few puzzle that are tied/bassed around the varrious schools of magic as the adventure is set in a long forgotten swamp sunken wizard's college..

The party includes:
Swordsage 4//Warblade 4
Cleric 4//Bard 4
Dragon Shaman 4//Scout 4
Wizard 4//Archivist 4

Also if you have a few ideas for encounters for the area it would be helpfull. I've already got a few Construct, living spell, and magical creature encounters prepared (my favorite being a altered Chimeria thats has a gorgon head instead of a dragon.)The Cr can be a bit higher as the defeated a Cr 9 boss last adventure by themselves and are currently traveling with 3 NPC level 5,6,and 9 respectively.

Anyway thanks in advance for any insight/ help you provide
Fallenibilis

 

[Dandu]

A lever in the middle of an empty room, and an ominous looking metal door on the other end.

The lever does not do anything, it just sits there.

The door is unlocked.

Watch the party go nuts.

 

[LostSoul]

What about a gamble?

You have some kind of strange machine that pumps out <<good stuff>>. But there's a good chance that it will pump out <<bad stuff>>, including monsters and PC-changing things (like "You can no longer lie" or "Your eyes turn black" or "You give off a horrid stench, which requires a save to resist but you can't hide with it").

Make the gamble based off player skill and character ability and tied to something else in the dungeon that gives a hint on how to put the odds in your favour. ("Oh hey, that mosaic makes me think I should cast Tongues and that will give me an edge here.")