Roll After Dark

Gags

Something in the mouth that makes speech hard or impossible.

Why people do it
A gag removes the running commentary and the possibility of talking your way out. What is left is sound rather than words, which is exactly what some people want to hear and others want to make.
Smallest way in
A hand over the mouth first, for a minute. That is a gag with an instant undo, and it answers the question before you buy anything.
What to watch
A gag ends the verbal safeword, so a non-verbal one must be agreed first — an object held in the hand and dropped is the most reliable. Nobody gagged is ever left alone. Watch for choking on saliva, and never gag anybody who is congested or has been drinking.
In the planner
15 different things carry this tag, and switching it off removes every one of them. The mildest of them sits at easy.