Instant

Instants, like sorceries, represent one-shot or short-term magical spells. They are never put onto the battlefield; instead, they take effect when their mana cost is paid and the spell resolves, and then are immediately put into the player's graveyard.
==Description==
Instants are the only card type in Magic to have no timing restrictions. They can be played at any time one has priority, including during other player's turns and while another spell or ability is waiting to resolve. 
==Rules==
===Subtypes===
The subtype for instants is called spell type and shared with sorceries.
==Friendly to instants==
Blue and red are the two colors that most appreciate instants and reward the player for playing them.
==Legendary instants==
The Lord of the Rings: Tales of Middle-earth debuted legendary instant cards that capture extraordinary moments from characters' pasts. These powerful spells can be unleashed only with the assistance of a legendary creature or planeswalker on your side of the battlefield.Dominaria Release Notes
You can't cast legendary instants unless you control a legendary creature or a legendary planeswalker. Once you begin to cast a legendary instant, losing control of your legendary creatures and planeswalkers won't affect that spell. Other than the casting restriction, the legendary supertype on an instant carries no additional rules. You may cast any number of legendary instants in a turn, and your deck may contain any number of legendary cards (but no more than four of any with the same name).
==Instant speed==
The informal term "instant speed" means "whenever you would be able to cast instant spells". This is most often used by the keyword Flash, granting "instancy" to any card type. Some abilities have "sorcery speed" baked into their rules, and some cards allow them to be activated "any time you could cast an instant". However, the timing restriction has been used to turn mana abilities into non-mana abilities, most famously <c>Lion's Eye Diamond</c> - this is to prevent it from casting spells, as part of the process of casting a spell is putting the spell from the hand onto the stack before paying costs. Starting with Strixhaven: School of Mages, the card text "only any time you could cast an instant" was shortened to "activate as an instant." 
The opposite of instant speed is sorcery speed.
==Obsolete card types==
The cards with the types mana source or interrupt became instants.
==Hypothetical change==
To simplify the rules, the developers discussed changing Instant from a card type to a supertype, so that it may be added to any card. This would mean flash could be removed as a keyword. All current cards with flash would instead have the "Instant" supertype. Any cards that are currently instants would instead be a "Sorcery" with the instant supertype. 
This change is unlikely to occur due to inertia.
==References==