Riftbound keyword
Reaction
Reaction is a Riftbound keyword: you can play the card or ability in response to a spell or ability on the chain, and it resolves first. It also works in showdowns.
129 cardsFirst seen in OriginsCore Rules 813
Official text
On the cards
Reaction (Play any time, even before spells and abilities resolve.)
Reaction (Play any time, even before spells and abilities resolve, including to a battlefield you control.)
Core Rules
- 813.1
- Reaction is a Permissive keyword.
- 813.1.b
- Reaction grants the corresponding card or effect all abilities and permissions of Action.
- 813.1.c.1
- On Cards: "This can be played during Closed States on any player's turn."
- 813.1.c.2
- On Activated Abilities: "This can be activated during Closed States on any player's turn."
- 813.2
- The corresponding card or effect with this keyword is not restricted to Closed States or Showdowns. This permission is inclusive of all other timings and options available to the ability as written, Action's permissions, or by default.
- 813.3.a
- Playing Units with Reaction still has the inherent restrictions of playing Units without Reaction. It can only be played to the controlling player's base or a battlefield they control.
- 309.1.a
- Only cards and abilities with the Reaction keyword can be played or activated in a Closed State.
- 159.2.b.3
- This will result in this spell resolving before spells and abilities that are already on the chain.
Riftbound Core Rules, updated October 9, 2026
How Reaction works
When can I play a Reaction?
Whenever you have priority: at the normal time on your own turn, during showdowns, and while a spell or ability is on the chain, on either player's turn. That last window is what lets you answer something before it resolves.
Core Rules 813.1.b, 813.1.c.1, 813.2, 309.1.a
Why does my Reaction resolve first?
The chain resolves its newest item first. A Reaction you play in response goes on top of what you're responding to, so it resolves before it.
Core Rules 340.1, 159.2.b.3Unleashed Rules FAQ and Clarifications
Does "play any time" really mean any time?
Not quite: you still need priority. On your opponent's turn, you get it once they put something on the chain and during showdowns, but not while their turn is otherwise quiet. Moving units doesn't use the chain, so a move itself can't be reacted to.
Core Rules 312.2.b, 312.2.d, 316.5.b, 448.3.c
Can I react to a unit or gear being played?
Not to the card itself. Units and gear resolve the moment they're finalized, before anyone gets priority. You can respond to their "when you play me" abilities, which go on the chain afterward.
Core Rules 337.2Core Rules: Radiance Patch Notes (Effective October 16, 2026)
Can I react to someone adding energy or power?
No. Abilities that add resources, including runes, also resolve as soon as they're finalized, and priority doesn't pass. A spell that adds resources can be answered like any other spell.
Core Rules 430.2, 430.2.a, 430.2.b
Do runes have Reaction?
Yes. Both rune abilities, exhausting for 1 energy and recycling for one power of the rune's domain, have Reaction, so you can use them whenever you need to pay, even partway through playing a card.
Core Rules 164.2.a, 164.2.b, 430.3Riftbound Core Rules: Patch Notes
Does Reaction let me play a unit to any battlefield?
No. Reaction only changes when you can play something. A unit with Reaction still enters at your base or a battlefield you control. Ambush is what lets a unit join a battlefield where you have units.
Core Rules 813.3.a, 822.1.b
Which other keywords give Reaction?
Hidden cards gain Reaction starting the turn after you hide them, Quick-Draw Equipment always have it, and units with Ambush have it while you play them to a battlefield where you have units.
Core Rules 811.6, 819.1.b, 822.1.b
Example: Flash dodges Void Seeker
You play Void Seeker to deal 4 to an enemy unit at a battlefield. Your opponent responds with Flash, a Reaction, and moves that unit to their base. Flash was played last, so it resolves first. When Void Seeker resolves, its target is no longer at a battlefield, so it deals no damage, but you still draw 1.
From Riftbound Core Rules
Official rulings
Riot's own words, from its rules articles.
CLARIFIED: Basic rune abilities have Reaction.
How does HOT FEPR actually work?
Executing items to the chain means a player adding an item to the chain when they have priority, or passing priority. When all players Pass priority in a row, the topmost finalized item on the chain Resolves.
Conditional permissive abilities might only be fulfilled while the card or ability with them is on the chain. In such a case, it can still be played or activated at the appropriate timing as long as doing so could fulfill the conditions.
What’s up with the reminder text on Chronobreak? Do I get to choose the order?
Pending chain items are finalized from oldest to newest and units resolve as soon as they’re finalized. … Then we finalize any play effects of those units in the order they triggered. Finally, players can react to the most recent item on the chain. If they don’t, that item resolves, and we repeat the process until all items on the chain have resolved.
Core Rules: Radiance Patch Notes (Effective October 16, 2026)
Every Reaction card (129)
kw:reactionCards with Reaction · 81
