Speed is a trait that players can have. It was introduced in Aetherdrift and is associated with the Start your engines! mechanic.^[1]

Description

The first time in a game you control a permanent with start your engines! your speed becomes 1. This happens immediately, so no one can respond and try to remove the permanent before you pick up speed. Once your speed is 1 or greater, you can trigger an ability to increase your speed. That ability is "Whenever one or more opponents lose life during your turn, if your speed is less than 4, increase your speed by 1. This ability triggers only once each turn." This ability isn't tied to any permanent. For the rest of the game, it can be triggered as long as your speed is less than 4, no matter what permanents you control.^[1]

Cards may reference your current speed and reward you based on that number.

Max speed

Once your speed is 4, you've achieved "max speed," and your speed can't go any higher. Some cards have abilities that care if you have max speed. These abilities are noted with "Max speed — [Ability]." That means that as long as you have max speed, meaning your speed is 4, the permanent has the stated ability.^[1]

Rulings

If you haven't started your engines and don't have speed yet, that number is 0.

References