Combo · ENGINE

107.3.c and 107.3.d price a facedown card in CONTROL, and 190.4.b is the one window that freezes it - so the Mushroom Pouch draws a card a turn for a spell you never play, and the only thing that can take it is losing the battlefield outside a combat

6 cards · mind · verified

Pieces

• Mushroom Pouch ×3 OGN-101 · payoff · mind

  At the start of your Beginning Phase, if you control a facedown card at a battlefield, draw 1.

• Smoke and Mirrors ×3 UNL-083 · engine · mind

  [Hidden] (Hide now for 1 Power of any domain to react with later for 0 Energy.) [Action] (Play on your turn or in showdowns.) Choose a unit you control and another unit you control at a different location. If at least one of them has [Temporary], move each to the other's location. Draw 1.

Payoff

Deck

• Both cards are mono-Mind, so 103.1.b needs only a legend carrying Mind. Measured over data/cards.json on 2026-09-12 that is sixteen legend NAMES: Daughter of the Void, Nine-Tailed Fox, Swift Scout, Herald of the Arcane, Lady of Luminosity - Starter, Mechanized Menace, Fire Below the Mountain, Prodigal Explorer, Chem-Baroness, Virtuoso, Bashful Bloom, Scorn of the Moon, Deceiver, Curator of the Sands, Defender of Tomorrow, Soul's Reflection.
• Neither is a Signature card (checked against data/cards.json), and neither appears in data/legality.json in any format - checked 2026-09-12, and data/legality.json's only non-banned row is the Wuju Bladesman starter legend, restricted in 2v2, which is Calm/Body and not a legend this line can use.
• You must CONTROL a battlefield to hide anything at all (107.3.c, 811.1.b), so this engine cannot start on turn one - 190.1 leaves both battlefields uncontrolled at the start of a Duel.
• One facedown per battlefield (107.3.b), and 485.4 puts two battlefields on a Duel table, so the ceiling is two facedown cards at once however many [Hidden] cards the list runs - which caps the Pouch at one draw per copy per turn, not per hidden card.

Run play

• the Pouch draws until one spell kills both holders

Prerequisites

• THE ZONE IS THE RULE, AND THIS PROJECT HAS BEEN DERIVING IT FROM THE KEYWORD. 107.3.a gives every battlefield its own Facedown Zone; 107.3.b sets its maximum occupancy at one card; and 107.3.c is the tenure clause: 'Cards can only be placed in or occupy the Facedown Zone if the controller of the card also controls the associated Battlefield.' The word that matters is OCCUPY, not merely 'be placed in' - control is a continuing requirement, not an entry condition. 107.3.d then executes it: 'If a player loses Control of a Battlefield, any cards in the Facedown Zone associated with that Battlefield are removed during the next Cleanup.' The catalogue has been sourcing all of this to the tail of 811.1.b ('for as long as you control that battlefield'), which says the same thing for [Hidden] only; 107.3.c and 107.3.d say it for any effect that puts a card face down, and they are cited by exactly two entries, both about denying the OPPONENT's hidden cards (warden-saboteur-hidden-lock, warden-tianna-base-lock) and neither about the cost of your own.
• AND 190.4.b IS THE ONE WINDOW WHERE IT CANNOT BITE. 'While a Combat or Showdown is ongoing at a Battlefield, Control of that Battlefield cannot change until instructed by steps of the Combat or Showdown.' It is cited by nothing in this project. Read with 107.3.d it settles a question every [Hidden] entry leaves open: a facedown card at the battlefield the opponent is ATTACKING is safe for the whole fight, because Control cannot move until 466.5 says so - so your hidden [Action] removal is always live inside the very combat that threatens it (464.2.f.1, 464.2.g), and a hidden [Reaction] card is live in every Closed State the combat opens (813.1.c.1). You never lose the card before you get to use it.
• THE COMPANION IS AN ANTI-SYNERGY AND IT IS EXACT. The evacuation family of this catalogue works by walking your last body off a battlefield so 323.6 strips your own Control in an Open State - and 107.3.d then throws away any facedown card you had there at that same Cleanup. So a [Hidden] package and an evacuation package want opposite things from the same battlefield, and a list running both must hide at the battlefield it is NOT going to abandon. 190.4.b is why the exception is exactly the combat window and nothing else: outside a Combat or Showdown, Control moves freely and the facedown goes with it.
• THE ARITHMETIC, WITH THE QUANTITIES DECLARED. One Mushroom Pouch is E2 once; hiding Smoke and Mirrors is one rainbow Power once (811.1.b). From the next Beginning Phase that is one card every turn, forever, for nothing - and the hidden card is not spent, so the engine and the payload are the same card. Three Pouches (103.2.b) are three draws a turn off ONE facedown card, because each Pouch is its own trigger and the condition is 'if you control a facedown card at a battlefield', not one per card. Two battlefields (485.4) let you hide a second card for a second rainbow, which changes nothing for the Pouch and buys a second payload.
• AND THE DRAWS ARE THE DANGEROUS HALF IN AN EMPTY-DECK SHELL. 431.1.a burns you out on a draw past the Main Deck and 194.1.d gives the opponent a point for it, so three Pouches firing every Beginning Phase are three forced draws a turn with no 'may' anywhere in the clause. In a loop shell built on the four-draws-per-pass ledger this is a liability, not a gain; it is an engine for a deck that still has a deck.
• WHY SMOKE AND MIRRORS AND NOT A CHEAPER HIDDEN CARD. The Pouch wants a card you are happy to leave face down indefinitely, which is the opposite of what every other [Hidden] payoff wants. Smoke and Mirrors is E2 with a cantrip attached, so playing it later for 0 (811.1.b) costs you nothing you were using - and 811.1.d.2 confines its targets to the battlefield it was hidden at, which is exactly the battlefield the Pouch has been paying you to hold. A hidden removal spell would be tempting but you would play it, and the turn you play it the Pouch stops.
• TWO MEASUREMENTS THIS ENTRY STANDS ON, BOTH MADE 2026-09-12 OVER data/cards.json. ZERO non-Equipment gear in the pool has the word 'here' in its text (74 non-Equipment gear base codes of 114 gear in all), which is why 152.2's rule that non-unit gear cannot normally reach a battlefield costs this pool nothing - a gear's Location is defined and no card reads it. And OGN-077 Zhonya's Hourglass is the ONLY non-Equipment gear in the pool that carries [Hidden], so it is the only one 152.2's facedown route could ever place at a battlefield.
• THE FACEDOWN CENSUS, NAMED AND SPLIT BY WORDING, MEASURED OVER data/cards.json ON 2026-09-12. Nine cards reference a facedown card outside the [Hidden] reminder text: OGN-101 Mushroom Pouch, OGN-181 Pack of Wonders, SFD-121 Black Market Broker, SFD-139 Edge of Night, UNL-014 Monster Harpoon, UNL-023 Katarina Reckless, UNL-053 Scuttle Crab, UNL-141 Evelynn Entrancing and VEN-099 Tornado Warrior. Only TWO of them pay for a card still face down rather than for playing it - the Pouch, every turn, and UNL-014 Monster Harpoon once (2 damage becomes 4 if you control a facedown card), which makes the Harpoon the natural second payload in a Fury shell and NOT a competitor for the zone. And the wording splits: SFD-121, SFD-139, UNL-141 and VEN-099 say 'from face down' while OGN-167 Ember Monk says 'from [Hidden]' for the same event, so a predicate on either phrase alone misses cards - which is how a first sweep of this family came back one card short.
• THE FACEDOWN ZONE IS NOT A LOCATION, AND IT IS THE SAME SENTENCE THIS PROJECT USES ON THE LEGEND ZONE (#204, from #187 batch 19). 107.4.b - 'This is not a location' - is cited 26 times here and is what kills the whole legend-plus-Reckoner's-Arena family, because 'here' cannot reach a zone that is not a location. 107.3.e is the identical sentence for the Facedown Zone and was cited by nothing in 766 entries. Three uncited paragraphs finish the profile: 421.3 gives a facedown card no properties of its own except what the hiding effect grants, so it is not a unit, has no Might and no domain; 107.3.f makes the ZONE public while the CARD is private, which is why 'if you control a facedown card' is a legal thing for a card to read; and 421.4 reveals it to all players if it changes zones.

Bodies no card supplies

Take a battlefield and hold it

Steps

1. Take a battlefield and hold it. 190.1 leaves both uncontrolled at the start of a Duel and 107.3.c requires Control before anything can be hidden there.
2. Play OGN-101 Mushroom Pouch for 2 Energy. It is a gear, so 143.4 never exhausts it and its trigger carries no exhaust.
3. Hide UNL-083 Smoke and Mirrors face down at that battlefield for one rainbow Power (811.1.b). 107.3.b allows exactly one facedown card there.
4. From your next Beginning Phase the Pouch draws you 1 for holding it. Three Pouches draw 3 - the condition is 'if you control a facedown card at a battlefield', so one facedown card satisfies all three.
5. Do not play Smoke and Mirrors while the draws are worth more than the spell. It costs 0 whenever you change your mind (811.1.b), and it cantrips when you do.
6. The engine's only failure mode is losing that battlefield: 107.3.c stops the card occupying the zone and 107.3.d removes it at the next Cleanup.
7. It cannot fail during a fight. 190.4.b freezes Control for the whole Combat or Showdown, so the facedown card survives an attack on that battlefield and is playable inside it - [Action] in the opened combat (464.2.f.1, 464.2.g) or [Reaction] in any Closed State it opens (813.1.c.1).
8. Do not pair this with an evacuation line at the same battlefield: 323.6 strips your Control the moment your last body walks off and 107.3.d takes the facedown card with it.
9. Three copies of each (103.2.b). Nothing here loops inside a turn and nothing here scores; the draws are per Beginning Phase and are NOT optional, so watch 431.1.a.

Per iteration

one card per Mushroom Pouch per turn, for one rainbow Power spent once and a spell you keep rather than cast

How it ends

engine only - nothing here scores. It runs for as long as you control the battlefield the card is hidden at (107.3.c, 107.3.d), with 190.4.b guaranteeing it survives any combat there; the draws are mandatory, so 431.1.a ends it when the Main Deck does

Sources

Published elsewhere

• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 107.3.a and 107.3.b 2026-07-16
• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 107.3.c and 107.3.d 2026-07-16
• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 190.4.b 2026-07-16
• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 152.2 and its worked example 2026-07-16
• Card text, data/corpus_flat.txt (built from Riot's gallery content API by scripts/build-cards.mjs) 2026-09-12

Walked here, in this project

• Hand walk 2026-09-12 (docs/phase0/walks/2026-09-07-uncited-rules-blocks.md), batch 17 2026-09-12 record

Walked against Core Rules 2026-07-16

Match a deck list against the whole catalogue