Article:
D&D 4th ed: The Wizard Lair

Adventurers need magical loot, and what better place to go get some than the lair of a wizard?
The home and working place of a wizard should be something exotic and very dangerous for the unwary, uninvited player character. After all, wizards usually have a ridiculously high intelligence score.
To add some additional flavor to your Wizard Lair, I have crafted a random roll table for you, and I suggest you use it at least a couple of times for each lair.

Wizard Lair Features Table.
Roll 1d20
1- Within the rooms, wandering, caged or nestled here and there, are monstrous creatures that have been polymorphed by the wizard into the form of harmless insects, vermin or small pet animals.. perhaps that is not actually a goldfish in a bowl, but a polymorphed Rust Monster? These will return to normal form if anyone casts a dispel magic effect, or on any trigger or command word set up by the wizard.
2- Living spells, magical creations with a semblance of life, a wandering fireball, a skittering bolt of lightning, roaming the halls of the wizard's domain, looking for a target.
3- Petrified creatures set as statues and triggered to return to a living form when careless interlopers step where they should not.
4- Illusionary duplicates of the wizard, walking around reading scrolls, muttering at desks full of musty tomes, and otherwise engaged in day-to-day wizard behavior, all decoys to confuse would-be assassins.
5- Test Golems, poorly put together experiments that have been set to menial tasks, sweeping, dusting, stacking and cooking.
6- A bridge which rises to meet the feet of those who speak the right words, or areas which will shift gravity from vertical to horizontal at a spoken command, even zones which are set to be filled with swarms of insects or spinning barriers of blades, all ready and waiting for the wizard to activate.