From GMod Wiki
|Description||This event modifies the sensitivity of the mouse by returning a multiplier that modifies how much the mouse was moved that frame.|
|Returns||float or nil|
- As an example, if this function were to return 5 and you moved the mouse to the left 5 pixels, it would be as if you moved the mouse 25 pixels to the left (because 5*5 = 25)
- If you return zero, the player won't be able to look around anymore.
- Returning nil is the same thing as returning 1