A Deputy is a flavor name for a Backup Cop. Once a Cop has died, the Deputy will become an ordinary Cop (the flavor logic being that the Deputy steps up to replace the deceased Cop). The Deputy may or may not be self-aware (if not, they will receive a Vanilla Townie Role PM). Occasionally a self-aware Deputy is called a Retired Cop.
This role does not necessarily make any guarantee about the existence of a Cop in the setup to begin with. If there is no Cop, this role is effectively a Named Townie. On the other hand, if there are multiple Cops in the setup, the Deputy will traditionally inherit the sanity of the first deceased Cop.
This role is virtually always pro-Town.
This version of Deputy, and only this version of Deputy, is considered Normal on mafiascum.net.
An older variant is that the Deputy can choose to 'retrieve' the results of a dead Cop's investigations instead of becoming a full Cop. If there is more than one Cop, the deputy usually can only get the results of one of the Cop's investigations, so they must choose wisely when and on whom to use their ability.
Use and Power
A Deputy is used to ensure that the Cop role stays in the game even if the first person holding the role dies. To that end, it is vaguely similar in power to giving a Cop one shot of death immunity. This is fairly good for Town; so Deputy is not often seen except in games with variable sanity, Cop-themed games, or in games with no Cop at all.