Retainer

Retainers or hirelings are backstops-for-hire in role-playing games. Often playfully nicknamed "henchmen" but that term is vague.

Retainers have helped out undermanned gaming-tables since the old days of Dungeons & Dragons. Tom Moldvay in Basic Dungeons & Dragons detailed them in his red Basic book but warned inexperienced DMs away from using them yet. For Moldvay, they are NPCs with their own level-progression; but they don't make their own decisions, so make only half the XP. Which is not to say that the retainer will obey every command; there's a loyalty-check mechanic. Moldvay believed that the hiring of retainers should itself be a roleplaying opportunity.

Moldvay promised "hirelings" at the Expert level. The actual blue book we got detailed all sorts of specialists and mercenaries that might be hired to work on specific tasks beyond "take the pie away from the orc".

As lower-deck sorts of NPC, traipsing around a party of characters whose players tended either very young or socially-inept, the farcical potential of a "henchman"-focused storyline became too good to pass up. Knights of the Dinner Table and (especially) Nodwick explored these themes to great effect, landing both comics runs in Dragon Magazine.