The Trampoline is a shaman item that consists of a small plank with a bluish projection on one side of it. When a player falls onto the trampoline, the player will bounce off the trampoline at a higher height or speed. After bouncing on a trampoline, a mouse is capable of Air Jumping, even if it jumped onto the trampoline prior. Trampolines are only available to the Shaman in certain maps, and are generally used to bounce to the cheese when it is high over the mouse's head; or over obstacles, such as walls or fans.
To best utilize the trampoline, jump while at the height of your bounce.
When placing a trampoline, note whether you will need to stabilize it. Sloping surfaces, unsteady constructions, loose objects, or wind can all negatively affect the usefulness of a trampoline to your mice. If your trampoline needs securing, any of a number of techniques will suffice. Also, note that in maps where mice collide with each other, a falling mouse will negate the rise of a mouse attempting to use the trampoline. Placing a trampoline under a crowd of colliding mice is an exercise in futility. It is much easier to anchor the trampoline so that other mice won't push it off.