Most props can be manipulated in some way using Prop_ helper functions (and normal Entity_ helper functions).

Very straightforward - a prop which can have illumination switched on and off with Lamp_SetLit. Often connected to additional in-level lights. Can be controlled through Lamp_ helper functions.

A physics-based prop that can be picked up, turned and examined by the player. Make sure the body mass isn't 0!

A physics-based prop that can be grabbed and pushed around (but not picked up).

A turnable wheel, such as a valve wheel. Must have a Hinge joint. Can be controlled through Wheel_ helper functions.

The basic physics-based object; can't be interacted with by default.

An object with a body in it that can be grabbed and slid along a joint e.g. a drawer. Must include a Slider joint. Can be controlled through Slide_ helper functions.

A door that swings. . Can be controlled through SwingDoor_ helper functions.

A button that can be locked, disabled or enabled. Can be controlled through Button_ helper functions.

An object which, when interacted with, will load a new level. Nearly obsolete now due to level streaming.

An object which can be smoothly moved or rotated between two different points e.g. a ladder that slides into place, or a wall that turns to reveal a secret passage, or a cargo lift. Use MoveObject_ helper functions.