Epic

Epic is a keyword ability of five sorceries from Saviors of Kamigawa. In keeping with that block's legendary theme, its design is intended to provide an answer to the question "What does it mean for an instant or sorcery to be legendary?"

History
The ability has appeared on only one cycle of five cards, all sorceries:
 * White: Enduring Ideal (Search your library for an enchantment and put it onto the battlefield)
 * Blue: Eternal Dominion (Search target opponent's library for a non-planeswalker permanent and put it onto the battlefield)
 * Black: Neverending Torment (Exile cards from target opponent's library equal to the number of cards in your hand)
 * Red: Undying Flames (Deal damage to target creature or player equal to the CMC of the first nonland card you exile from the top of your library)
 * Green: Endless Swarm (Get a 1/1 token for each card in your hand)



Description
An epic spell is copied in its controller's upkeep on every turn for the rest of the game. If it has any targets, the player may choose new targets for the copy.

In exchange for this powerful ability, the player can't cast spells for the rest of the game. Since copies of a spell aren't cast, the epic spell's copies aren't affected.

According to Mark Rosewater, Epic is probably the mechanic with the least design space.

Interactions
Here is a list of things an owner of an epic spell can do after an epic spell has been played and resolved.
 * They still have all phases, which means they will still untap, draw, attack, block, discard (using madness, however, is not allowed; it is casting a spell for an alternative cost), etc.
 * They can still play lands; this is a game action that only requires the stack to be empty and the player to have priority during a main phase of their turn.
 * They can use activated abilities on permanents of theirs that are on the battlefield.
 * They can use abilities which work outside of the battlefield. For example, you can cycle cards as this isn't playing spells. (Some cycling actually triggers some abilities on the cycled card, e.g. when Decree of Pain is cycled, all creatures get -2/-2 until end of turn; this is still not casting.)
 * They can put a copy of a spell on the stack (e.g. Chain Lightning).
 * They can use channel abilities.