What it does
Equip is an activated ability on Equipment artifacts that lets you attach the Equipment to a creature you control by paying its equip cost. You can only activate equip at sorcery speed—during your main phase with an empty stack—and only target creatures you own and control. There's no limit to how many times you can equip in a turn if you can pay repeatedly.
The most common mistake: equipping is not the same as casting. The Equipment is already on the battlefield, so moving it doesn't use the stack the way a spell does, and it can't be "countered" by counterspells. Also, if the equipped creature leaves, the Equipment simply stays on the battlefield unattached—it doesn't die with the creature.
In Commander, equip cost matters because moving Equipment around to dodge removal or chase a board state can be mana-intensive, and you can only do it on your own turn—so plan attachments before combat.













