Potion Attack

Set up stares like this
Corridor

Make a corridor as long as you want
Drop

Make a drop like this so the player does not know what's coming
Potions

Fill the dispensers with potions of harming
Redstone

Put the Redstone over the dispensers
Activated

Switch the world to survival unles you made it in survival so the next player to try to steal your stuff will get recked by magic