# Riftbound Timing Keywords Explained: Action, Reaction, Hidden & Ambush

_2026-08-12 · RiftCompare_

How Action, Reaction, Hidden and Ambush change WHEN a Riftbound card can be played — instant-speed tricks, facedown surprise plays, and dropping a unit into a fight already in progress.

Riftbound splits a turn into states — Open, Showdown, Closed — and most cards can only be played during your own Open state, on your own turn. Four keywords exist purely to carve out exceptions to that: Action, Reaction, Hidden and Ambush. None change what a card does — only when and, for two of them, where it can be played.

## Action: permission to play during a Showdown

**Action lets a card or ability be played or activated during a Showdown, even on your opponent's turn** — a state that would otherwise lock most cards out. It's pure permission: an Action unit still has to be played to a base or a battlefield you control, exactly like normal. Full reference: **[Action keyword page](/keywords/action)**.

## Reaction: true instant speed

**Reaction includes everything Action grants, plus permission to play during a Closed state** — Riftbound's tightest timing window, and the closest thing the game has to a universal "any time" instant. A Reaction card can respond on either player's turn, which is what makes Reaction cards feel like tricks and counters rather than ordinary plays. Full reference: **[Reaction keyword page](/keywords/reaction)**.

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## Hidden: pay now, play later as a surprise

**Hidden lets you pay a cost to place a card facedown at a battlefield you control.** From the next turn on, that facedown card gains Reaction and can be played for free — your opponent has no idea what it is until it resolves. The tradeoff: targeting from a Hidden play is usually restricted to the battlefield it was hidden at, since the card already committed to a location the moment it went facedown. Full reference: **[Hidden keyword page](/keywords/hidden)**.

## Ambush: dropping into an ongoing fight

**Ambush lets a unit be played to a battlefield where you already control units** — normally off-limits, since units can usually only go to your base or somewhere you already have presence — and grants it Reaction for that specific play. Full reference: **[Ambush keyword page](/keywords/ambush)**.

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## Building a tempo deck around timing keywords

Hidden and Ambush are natural partners: hide a threat one turn, then Ambush a second unit into the same fight the next, and your opponent has to play around two unknowns instead of one visible board. Reaction abilities that Add resources let you hold energy back and still cover a cost you didn't fully plan for. None of these four keywords do anything on their own — their value is entirely in disrupting what an opponent thinks they know about the board, which is exactly why a deck built around them rewards patient, information-heavy play over straightforward curve-outs.

See the full **[Riftbound keywords glossary](/keywords)** for every mechanic in the game, including the set's headline new keywords in the **[Empower](/guides/riftbound-empower-explained)**, **[Flow](/guides/riftbound-flow-explained)** and **[Burn](/guides/riftbound-burn-explained)** guides.

## FAQ

**What's the actual difference between Action and Reaction?**

Reaction includes everything Action grants — permission to play during a Showdown — plus the additional permission to play during a Closed state, Riftbound's most restrictive, truly any-time timing window. A card only needs Reaction to get both.

**Can you play a Hidden card the turn you hide it?**

No — a hidden card only gains its free cost and Reaction-speed timing starting the next turn, not immediately.

**Can Ambush put a unit on an empty battlefield?**

No — Ambush specifically requires a battlefield where you already control one or more units; an empty battlefield isn't a valid Ambush destination.

**Do these keywords change what a card does?**

No — all four are pure permissions. They change when and where a card can be played, never its actual effect once it resolves.

**Are Action, Reaction, Hidden and Ambush new to Vendetta?**

No — they're core Riftbound timing rules, not set-specific mechanics like Empower, Flow and Burn.

Source: https://riftcompare.com/guides/riftbound-timing-keywords-explained