Combo · ENGINE

Possession — the Defender's [Action] window inside an opened Combat

1 card · chaos · verified

Pieces

• Possession ×1 OGN-203 · engine · chaos

  [Action] (Play on your turn or in showdowns.) Choose an enemy unit at a battlefield. Take control of it and recall it. (Send it to your base. This isn't a move.)

Payoff

Deck

• Legend domains cover Chaos. Possession is mono-Chaos, so any legend with Chaos runs it.
• A garrison of your own at a battlefield you control — the line is a defence, so the battlefield has to be worth defending.

Prerequisites

• THE WINDOW IS THE ONLY ONE A NON-TURN PLAYER HAS, AND [Action] IS THE WHOLE PERMISSION. 155: "A spell can be played during an Open State outside of Showdowns on its controller's turn" — neither half of that is true here. 312.2.a gives Priority "When the turn is in a Neutral Open State during their Main Phase", which is the opponent's Main Phase, not yours. What opens the door is 806.1.b: "Action grants the corresponding card or effect permission to be played or activated during Showdowns, even when it is not the Controlling player's turn" (806.1.c.1 spells it out as "This can be played during showdowns on any player's turn"; 806.2 keeps every other timing besides). The chain of Focus is printed: 464.2.d "The Attacker gains Focus", 347.2.b "Otherwise, Focus passes to the next Player in Turn Order", 312.2.b "When the turn is in a Showdown State and they gain Focus", 347.1 "Play a Card or Activated Ability that is legally timed".
• THIS IS NOT #58's PRE-OPEN WINDOW, AND THE DIFFERENCE IS ONE CLAUSE. 323.10 is scoped "before it has opened", which is why charm-evacuate-conquer has to cast the evacuation BEFORE the entering move and why only a Triggered Ability reaches that gap. Here the Combat has already opened at 464.2, so 323.10 cannot apply and 461 ("Combat is considered Staged if there are units controlled by two opposing players at a Battlefield but the Steps of Combat have not been initiated") means it is no longer even Staged. The spell is played AFTER the move, on the other player's turn, and it is legal for one reason only: 806.1.b.
• THE COMBAT IS WON WITH NO DAMAGE, AND 465.3 IS NOT AN ELSE-BRANCH — ONE CORRECTION TO ISSUE #118. 465.1 reads "If both Attacking and Defending units remain at this battlefield, the following Tasks become Outstanding, in the specified order", and BOTH 465.2 (resolve Combat Damage) and 465.3 ("Skip the FEPR process and cancel any outstanding tasks. Proceed to the Resolution Step") sit inside that gated list. #118's C1 wrote "465.3 applies instead"; it does not apply at all — with the Attacking side empty no task becomes Outstanding and the game simply reaches Step 3. Either way no damage is dealt in either direction. 466.1.a.2 inserts "3d. Recall Attackers present at the Battlefield if Defenders are still present" — no Attackers are present, so nothing is recalled and 466.3.d's "No Result" ("if units were recalled during step 3d") never arises. 466.3.a: "A Player has won a combat if they received either the attacker or defender designation and are the only Player that has units remaining at this battlefield during this step."
• IT DOES NOT CONQUER, AND ISSUE #118 SAYS IT DOES — THE SECOND CORRECTION. 466.5 is conditional: "If no Showdown or Combat is staged at this location, the player with Units remaining here Establishes Control if they didn't already control this Battlefield", and 466.5.d hangs the Conquer on that Establishing ("Establishing Control results in a Conquer if that player has not yet scored this Battlefield this turn"). 464.2.c.2 makes the Defender "the player who did not apply the Contested status", and a player sitting on a battlefield they do not control applies Contested themselves at the next Cleanup (323.11.a) and becomes the Attacker — so a Defender always already controls the battlefield and 466.5 does nothing for them. What this line buys is the negative: no damage taken, the garrison intact, and Control kept, so 315.2.b.2 ("The Turn Player Holds all Battlefields they Control") and 469.2 pay the point in YOUR next Beginning Phase. The point comes from the Hold, never from this combat.
• THE ATTACKER-SIDE USE OF THE SAME SPELL IS ALREADY CATALOGUED AND IS NOT REPEATED HERE. Played by the turn player on their own attack, the same removal empties the DEFENDING side and 466.5 does then Establish Control with 466.5.d making it a Conquer — but that is card for card the rule chain sinister-poro-attack-evacuate already walks (464.2.e → 465.1 fails → 466.3.a → 466.5.d), and UNL-137 does it for 1 Energy with no spell at all. [Action]'s value is strictly that it reaches the other player's turn, which no Triggered Ability of yours can.
• THE ARITHMETIC WITH THE QUANTITY DECLARED, AND WHERE THE MANA COMES FROM. 167: "Every player's Rune Pool empties at the start of each player's Main Phase and the end of each player's turn" — so you start the opponent's Main Phase with nothing and must build E8 + 3 Chaos Power inside their Showdown. Both rune abilities carry the permission: 164.2.a "[E]: [Reaction] — Add [1]" and 164.2.b "Recycle this: [Reaction] — Add [C]", and 813.1.b gives Reaction "all abilities and permissions of Action". 164.2.b has no exhaust in its cost, so the same rune pays twice: eight ready runes give the 8 Energy, and three of those eight, if Chaos, then recycle for the 3 Power. The real price is therefore EIGHT RUNES LEFT READY THROUGH YOUR OWN TURN — you spent nothing on your own turn — plus three of them gone to the Rune Deck (161.2.b), and 315.1.b readies the rest only at your next Awakening. One Possession removes ONE unit, so the line closes only against an attacking force of exactly one, the same bound charm-evacuate-conquer carries.
• THE CHEAPER MEMBERS OF THE SAME WINDOW, PRICED, AND WHY POSSESSION STILL HEADS THE ENTRY. All are [Action] spells that remove a unit at a battlefield and none carries a [BANNED marker: OGN-172 Rebuke (Chaos, E2 P2, "Return a unit at a battlefield to its owner's hand") is the cheapest complete line and needs only two ready Chaos runes; VEN-106 Wind and Ghosts (Chaos, E3 P1, "If it has 3 Might or less, banish it. Otherwise, return it to its owner's hand") is the cheapest that can remove permanently; OGS-012 Blast of Power (Order, E6 P1, "Kill a unit at a battlefield") is unconditional but 103.1.b.1 puts it in a different deck, since it needs an Order legend. What Possession alone adds is the second half of its own printed text: the attacker is not merely removed, you keep it. 191.1/191.3 make you its Controller and 455 ("a Permanent is relocated from anywhere to its Base without it being a Move") with 456 sends it to YOUR base, which the card's own reminder states — "Send it to your base. This isn't a move." Your side gains the body the opponent spent their turn attacking with.
• THE DRAWBACK IS THE OPPONENT'S OWN FOCUS, AND WAITING DOES NOT HELP. 347.1.b: "When that Chain closes, Focus passes to the next Player in Turn Order", so after your spell resolves the attacker gets a window and can add a body; 464.2.c.3.a designates any unit that becomes present later "during the Cleanup phase following the action that caused it to become present", so a refilled attacking side restores 465.1 and the Damage Step runs normally against your garrison. Nothing is stripped mid-combat either: 323.6 only acts "if the turn is in an Open State and there is no Showdown or Combat ongoing there", and 190.3.b keeps the battlefield Contested "until Control is established or re-established".
• 2V2 (489) DOES NOT CHANGE THE LINE, BUT IT CHANGES WHAT IT IS WORTH. 489.1 puts four players in the game, 489.5.c.1 alternates the teams, and 489.3 sets "Victory Score: 11" against 194.3's default 8 — so you sit through three other players' turns per round-trip and this is the only window you have in all three. 489.8.a is a separate and narrower permission — "Players may play spells or activate abilities during their Teammate's Turn. In order to do so, their Teammate will invite them to play a spell or activate an ability using their own Priority" — an invitation on an ALLY's turn; against an opponent you still need [Action]. 489.8.e ("Friendly describes controlled Game Objects by a player or their Teammate") does not widen "enemy unit": the attacker is an opponent either way.
• THE THIRD LEG OF THE EVACUATION FAMILY, ADDED BESIDE 323.6 AND 323.10 (#204, from #187 batch 18). This entry already cites 323.6 for Control being stripped and 323.10 for a staged Combat un-staging. The Contested STATUS itself is a third thing and 190.3.b.1 is the paragraph for it, cited by nothing in 766 entries: 'If a player who applied Contested status to a Battlefield controls no Units there and there is no ongoing Showdown or Combat at that Battlefield, then Contested status is removed in the following Cleanup.' With 323.11, which removes Contested from the battlefield's side, the pair states it from both directions. The boundary worth carrying beside it is 190.3.d - 'At this time Game Effects cannot reference this status' - so Contested is real, it decides whether a Combat or a Non-Combat Showdown occurs, and no card in the pool can see it.

Steps

1. Hold eight runes ready through your own turn, at least three of them Chaos. 167 empties every player's Rune Pool at the start of every player's Main Phase, so nothing can be banked as Energy — only as unexhausted runes.
2. The opponent Standard-Moves a single unit into a battlefield you control and garrison. 450 and 190.3.a.1 make THEM apply Contested; the Cleanup stages a Combat (323.9) and 323.13 opens it.
3. 464.2.c.1 and 464.2.c.2 make them the Attacker and you the Defender, 464.2.c.3 designates the units, 464.2.d gives them Focus. Their attack triggers go on the Combat Chain at 464.2.e and resolve; 464.2.f.1 leaves the Combat Showdown Open and 464.2.g lets play continue.
4. They pass. 347.2.b hands you Focus and 312.2.b gives you Priority. Exhaust eight runes for 8 Energy (164.2.a) and recycle three Chaos runes for 3 Chaos Power (164.2.b); both are [Reaction] and 813.1.b makes that enough inside a Showdown.
5. Play Possession (806.1.b, 806.1.c.1, 347.1) on the sole attacking unit. You take control of it (191.1, 191.3) and it is recalled to your base (455, 456).
6. Everyone passes, 348 closes the Showdown and 348.1 sends the game to the rest of Combat. 465.1's condition fails, so no damage is dealt; 466.1.a.2 recalls nothing; 466.3.a gives you the combat; 466.5 leaves your Control untouched because you already had it. The point arrives at your next Beginning Phase from 315.2.b.2 and 469.2.

Per iteration

one enemy attack answered with no damage taken or dealt, the attacking unit permanently transferred to your base, and the battlefield still yours to Hold

How it ends

engine only — the combat itself scores nothing; the Hold it protects is one point per turn, bounded by 470, and the spell by the 3 copies of 103.2.b

Sources

Published elsewhere

• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt) 2026-07-16
• 2v2 and Combat-Showdown [Action] lens — issue #118 (GitHub) 2026-09-06

Walked here, in this project

• Hand walk 2026-09-06 2026-09-06 record

Walked against Core Rules 2026-07-16

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