Doctor

The Doctor is a quintissential Mafia role, found in almost any setup. It is invariably a Town role, although a Scum Doctor is a possibility in larger games.

Abilities
The Doctor may visit a player each night. If that player would have been killed that night, their life is saved instead. The Doctor may be told that they saved a person in the night, or they may not.

Common Variants

 * Veterinarian - Named after Yourself's role in Schmaltz; the Vet may only be effective against the kills of one role (in Schmaltz, could protect against SK but not against scum).
 * Quack - A Quack Doctor will be told in their role PM that they are a regular Doctor. Secretly, all their attempts to protect a target will fail. May or may not be revealed on death.
 * Backup - A vanilla role that acquires full Doctor powers upon the death of the original Doctor.

Uncommon Variants

 * Healer - A day doctor who can save a Poisoned or otherwise marked-for-death player from expiring at the end of the day.
 * Disgruntled Protector - Also known as the Defibrillator, this variant will protect a target from kills, but will kill the target instead if their protection goes unneeded.

Strategy
The Doctor's duty, beyond lynching scum during the day, is to protect roles relevant to the Town's best interests - Investigative roles, outed Lovers, or players who are leading the town are all suitable targets for protection.

Basically, anyone who looks like a good target for the scum nightkill.

A Doctor must also avoid being night-killed himself, either by being outed as the Doctor or looking too useful for the town in general. Because of this, a Doctor may have to forego leading the Town to best protect it.