the bait is a removal spell before the attack, and the answer is a counter during it

Issue #258 (a slice of #200), 2026-10-05. Constructed, Duel (485). Rules version 2026-07-16. Card text verbatim from data/corpus_flat.txt; rules pasted from data/Riftbound-Core-Rules-2026-07-16.txt. Read the unopposed clock for the baseline this is measured against.

Subject: resonating-strike-sunlit-guardian-hidden-reinforcement, the mono-Calm ENGINE that hides VEN-034 Resonating Strike at a battlefield you hold and, when the opponent attacks it, moves OGN-054 Sunlit Guardian in from somewhere else as a 6-Might [Tank]. The entry prices the arrival correctly. Walked as a game, the line survives the answer that broke the Poppy play — removal on the garrison in the opponent's Main Phase — because the hidden card is itself a [Reaction] and can be flipped in response. What breaks it is cheaper and narrower: a counterspell, at the one moment the facedown card stops being a secret.

Why this line. scripts/sequence-pick.mjs --unplayed, re-run on 2026-10-05 at d0cb346, reads 771 entries, 262 with forced-ordering language, 102 in the queue and 83 of them with no play — the same numbers the issue measured, so the queue did not move. The pick is by global rank, skipping entries that already have a play: this entry is rank 15 (two hits on before), first in the list. The other entry of this slice is rank 17, played in the Golds are a bank with no teller.

1. Needs

The card text the play turns on:

• Resonating Strike: "[Hidden] (Hide now for :rb_rune_rainbow: to react with later for :rb_energy_0:.) [Reaction] (Play any time, even before spells and abilities resolve.) Choose a battlefield you control and a unit you control at a different location. Move that unit to that battlefield and give it +2 :rb_might: this turn."
• Sunlit Guardian: "[Shield] (+1 :rb_might: while I'm a defender.) [Tank] (I must be assigned combat damage first.)"

2. What the trap costs, and what keeps it armed

The hide is the only payment. 811.1.b: "It is functionally short for "While this card is in your hand or in your Champion Zone on your turn during an Open State, you may pay [A] to hide this facedown at a battlefield you control that doesn't already have a facedown card hidden there for as long as you control that battlefield. Beginning on the next turn, this gains [Reaction] and you may play this, ignoring its base cost."

Two clauses of that sentence decide the whole play. Beginning on the next turn means a card hidden on your turn is live on the opponent's very next turn. For as long as you control that battlefield means the garrison is load-bearing: 323.6 — "4. Players lose control of any controlled Battlefields without their Units occupying them if the turn is in an Open State and there is no Showdown or Combat ongoing there." — and 107.3.d — "If a player loses Control of a Battlefield, any cards in the Facedown Zone associated with that Battlefield are removed during the next Cleanup." So the Poro never attacks; it stands there to keep the trap on the table.

3. The turns, going first

Mono-Calm. The opponent is building on the other battlefield and holding cheap removal.

turn   runes   your turn                                                  held for their turn
T1     2       Stalwart Poro to base                                      -
T2     4       Poro walks to A, Conquer (344.2 Showdown, no defender).    1 ready rune, and
               Sunlit Guardian to base: exhaust 3 runes for E3.          the trap (costs 0)
               Hide Resonating Strike at A: recycle one of those three
               exhausted runes for the [A] (164.2.b). 3 runes remain.
T3     5       Hold A: +1. Free to develop; the trap still costs nothing   the trap

• The trap is live from the opponent's T2. It was hidden in your T2 Main Phase, after the Conquer made A yours, and "beginning on the next turn" is their turn.
• Its price is one rune, once. The recycled rune goes back to the Rune Deck (161.2.b, "When a Rune is Recycled it is returned to the Rune Deck, not the Main Deck."), so the board is a rune short on T3 — that is the whole cost of the line, against a printed E2 + 1 Power.
• The Guardian has to stand somewhere else on purpose. The spell chooses "a unit you control at a different location", so the reinforcement is a body at your base doing nothing until the attack comes. It is also out of reach of every removal that says "at a battlefield".

Their T2, the attack. They move two bodies into A for a summed Might of 4 against the Poro's 2 + 1 ([Shield]). In the combat you flip the Strike for nothing; it moves the Guardian in and gives it +2. 323.2.a gives it the Defender designation before damage — "If there are Units present at the Battlefield the Combat is taking place at, but do not have a designation, they gain the same designation as their Controller now" — so it defends at 3 + 2 + 1 = 6, and 815.1.c.2 sends all four damage to it first: "Units without Tank are invalid assignments until all units with Tank have lethal damage assigned to them." Nothing of yours dies; your 9 kills both attackers.

4. Breaks to

Not the bait. The answer that broke the Poppy play was removal on the garrison in the opponent's Main Phase, before the attack. Here it does not work. OGS-003 Incinerate (Fury, E2, "Deal 2 to a unit at a battlefield.") on the Poro puts a spell on the chain, which is a Closed State, and the flipped Strike is a [Reaction] — 813.1.c.1: "This can be played during Closed States on any player's turn." You respond: the Guardian arrives at A while you still control it, the Poro dies, the Guardian stays, and 323.6 never takes A away. What the bait does buy is information: the trap is spent in their Main Phase, they see a 5-Might [Tank] before choosing where to attack, and they simply attack elsewhere. You traded a 2-drop and the trap for their E2 and kept the battlefield with a bigger body — a fair trade, not a broken line.

A counter, at the flip. Playing from facedown is a chain like any other — 811.1.c.3: "Playing a card from facedown (or "from Hidden") does open a chain." — and the Strike is a spell with a printed cost of E2 + 1, which is what OGN-045 Defy (Calm, E1 + 1 Power, "Counter a spell that costs no more than :rb_energy_4: and no more than :rb_rune_rainbow:.") reads: 206, "Effects that need to determine a card’s cost for any purpose always use its printed or copied cost, even if that cost is increased, decreased, or ignored as the card is played." Countered in the combat, the Guardian never moves, the Poro faces the attack alone and dies, and nothing comes back — 425.1.c: "Countering does not refund any costs paid to play a card, activate an ability, or trigger an ability." Breaks to OGN-045 Defy for E1 + 1 Calm Power, against your rune, your card, your garrison and the battlefield.

A deck without Calm has UNL-131 Abandon (Chaos, E2, "Counter a spell. Return it to its owner's hand instead of putting it in their trash.") and SFD-136 Hard Bargain (Chaos, E2, "Counter a spell unless its controller pays :rb_energy_2:."). Abandon gives the Strike back to your hand, so it can be hidden again for one more rune. The T2 table leaves one rune ready, so Hard Bargain counters the flip; leave two ready to pay it.

Or a big enough attack. The Tank wall is a toll, not a shield: lethal on the Guardian costs 6, so an attack of summed Might 6 kills it and 9 kills both. The opponent cannot field that on T2; by T4 it can, and the wall is then just a body.

5. Verdict

The line is good, and better than its entry says. The obvious answer — kill the garrison first — is answered by the same card it targets, because a hidden card is a [Reaction] card from the next turn. The real price is one rune, once, and the real risk is one counterspell in the window the flip itself opens. Against a Calm opponent with E1 + 1 up, hold the trap back until they have tapped out in their own Main Phase; against Chaos, leave two runes ready so Hard Bargain can be paid.

It scores nothing: it turns one attack on A into a lost combat for the attacker on T2, at a cost of one rune.

6. Not verified

I did not walk an attacker with [Assault], an attack on both battlefields at once (the Guardian can only go to one), or 2v2.

Leads

• The entry never names a counterspell. 811.1.c.3 makes the flip a chain, and OGN-045 Defy reads the Strike's printed E2 + 1 (206), so it is counterable for E1 + 1 Calm Power — the line's cheapest answer, and it is not in the notables.
• The entry does not say the garrison must stay. 811.1.b keeps the facedown card only "for as long as you control that battlefield", and 323.6 with 107.3.d removes it if the garrison walks off; the body holding the battlefield cannot be used to attack.
• Pre-attack removal on the garrison is answered by flipping in response (813.1.c.1); worth a notable, because it is the answer that breaks the Ambush-based lines built on the same idea.