List of Magic: The Gathering Keywords - Evergreen Keywords - Haste

Creatures with the haste ability are able to attack and tap to activate abilities on the turn a player gains control of them, instead of waiting until their controller's next turn (an effect dubbed "summoning sickness" prevents a creature from attacking or using abilities with the tap symbol unless its controller controlled it since the start of their last turn). Haste is an example of a retroactive keywording, as cards from almost every earlier set have possessed "may attack the turn come into play" or "unaffected by summoning sickness," which was replaced by the word "haste." It was later changed to include untapping to activate abilities as well. Creatures with haste are most often red.