Chaos, Chaos!

Hewwo! I'm making a multi-room trap that includes a random-effect-generator to make things more interesting (roll a d12 at the top of the round, affect the players/battlefield in some way), but I need some help coming up with effects. I'm not really looking for straight damage, more modifiers.

Plz help!

Tiny room/large guests - Everyone increases by 1 size. It’s probably gonna work best in an area with tight corridors and wider rooms for the squeeze rules to come into play.

Make every creature in the combat roll randomly to determine which of the 6 walls of the room is now the floor for them. Separates the fighters and casters - could be beneficial, could be a problem!

Everyone who touches the Macguffin becomes bright red. Seems innocent, then the Gorgon is released.

Is it cake? Only a roll when you go to use it will tell! That isn't your only sword, is it?

I used to do a big battlefield shake up. On a grid, roll a d8 for direction and a d6 for number of squares. I never made anyone go prone, just if you hit a wall or another creature, you stop. Good guys and bad guys alike. Sometimes it helps, sometimes it hurts. You never know.