Sim-boosting (also known as sim-blitzing, or blitzing) is technique whereby one or more individuals from a club's senior staff or other sims temporarily join a slow, dying, or new sim in an attempt to boost the sim's activity (i.e. re-spark interest from the players, or start a new sim off strong). When utilized repeatedly or for an extended period of time, sim-boosting can be a sign of inbreeding within a simming organization.

The term "sim-boosting" was coined by James West.