Can Riposte be used to counter your own spells?

Question

Accepted Answer

Yes. Riposte can target and counter your own spells. It is a [Reaction] (so you may play it in response to your own spell) and its instruction 'Counter that spell' does not restrict the spell to an opponent's, so you may choose any spell on the chain. When it resolves it will clear that spell from the chain and give the chosen friendly unit +Might equal to that spell's Energy cost this turn.

You may use Riposte to counter your own spells. Riposte has the Reaction permission to be played while spells/abilities are on the chain [813]. Its text directs you to 'Counter that spell,' and countering is the act of negating a card or ability on the chain — which may be any card or ability the game directs you to counter — so you may choose a spell you control that is currently on the chain [425]. When Riposte resolves it will counter that spell (clearing it from the chain; it does nothing and is not considered to have been played) and then give the chosen friendly unit +Might equal to that spell's Energy cost this turn [425.1.a] [425.1.b]. Note that costs already paid to play the countered spell remain spent (they are not refunded) — energy spent to play a spell remains spent even if the spell is later countered [FAQ:unleashed#21].

You (or your opponent) plays a spell; that spell becomes an item on the chain. Because Riposte is a Reaction, you may play it in response while that spell is on the chain [813]. When you play Riposte, choose a friendly unit and choose the spell on the chain you want to target (that chosen spell may be one you control). When Riposte resolves it will Counter the chosen spell, clearing it from the chain and causing it to do nothing [425.1.a] [425.1.b]. Also as part of Riposte's resolution, the chosen friendly unit receives +Might equal to that spell's Energy cost this turn. The spell's cost/energy spent is still meaningful for such calculations even if the spell is countered [FAQ:unleashed#21].

If the chosen spell's Energy cost becomes unavailable or 'null' by the time calculation happens (for example because of an interaction that makes that information inaccessible per 359.3.e.12), then the +Might calculation would be affected as described by that rule. If the chosen spell had an Energy cost of 0, Riposte will grant +0 Might. Countering a spell does not refund any costs paid to play it — energy and other costs remain spent even if the spell is countered [425.1.c] [FAQ:unleashed#21].

Short answer: Yes — you can use Riposte to counter your own spells. Reasoning and rules citations: Riposte has the [Reaction] keyword, which grants it the permission to be played while spells and abilities are on the chain (it can be played in Closed States on any player's turn) [813]. The text of Riposte instructs you to 'Counter that spell' — countering is the act of negating a card or ability on the chain and is performed when a game effect directs you to Counter [425]. Nothing in the Riposte text restricts the targeted spell to being an opponent's spell, so 'a spell' can be any spell currently on the chain, including one you control. When Riposte resolves it will counter the chosen spell (the countered spell does nothing and is cleared from the chain; it is not considered to have been played) [425.1.a] [425.1.b]. Riposte's second instruction gives the chosen friendly unit +Might equal to that spell's Energy cost this turn. The game's record of the spell's cost/energy spent is still meaningful even if the spell is later countered (costs aren't 'unspent' when a spell is countered), so you should be able to compute the +Might from that cost [425.1.c] [FAQ:unleashed#21]. Caveat/assumption: If an effect somehow made the chosen spell's cost information unavailable ('null') by the time that calculation must be made, then rule 359.3.e.12 would apply and the calculation could be null or ignored. The most defensible practical ruling given the provided rules and clarifications is that countering your own spell with Riposte is legal and the unit gets +Might equal to that spell's Energy cost (even though the countered spell is cleared and does nothing).