Player speed refers to the value set in options that defines how quickly players move throughout the map in Among Us. The host of a lobby can set the player speed inclusively between 0.5x and 3.0x, in increments of 0.25x. The default player speed is 1.0x.
Player speed is a game-changing mechanic. If the player speed is low, the ability of Impostors to use vents becomes significant since using vents will be a much faster way to move around the map than walking. However, this may draw suspicion if An Impostor manages to get somewhere quicker than a walking Crewmate. The low speed may also make it easier to win off of critical Sabotages, such as Reactor Meltdown, if players are far away from the point where the Sabotage can be resolved.
However, if the player speed is high, using vents becomes less useful as players can walk around the map as quick as or quicker than An Impostor can use a vent. Also, quickly moving players may come into a room and catch An Impostor using a vent as the time it takes to enter and exit vents are always the same.
If the player speed is high, Crewmates can quickly search the entire map for dead bodies, which may be a disadvantage to Impostors. However, Impostors can kill and then quickly move to a different location, sometimes on the opposite side of the map — which may balance this out. Also, if players are traveling quickly, they may miss dead bodies.