Combo · ENGINE

370.1.b.1 - Nocturne's 'as you look at me' is a REPLACEMENT EFFECT, not a trigger, so under a mass [Vision] grant he deploys with no chain item and, by 312.1.b.1, with no priority at all

6 cards · mind + chaos · verified

Pieces

• Gemcraft Seer ×3 OGN-100 · engine · mind

  [Vision] (When you play me, look at the top card of your Main Deck. You may recycle it.) Other friendly units have [Vision].

• Nocturne, Horrifying ×3 OGN-194 · payoff · chaos

  [Ganking] (I can move from battlefield to battlefield.) As you look at or reveal me from the top of your deck, you may banish me. If you do, you may play me for 1 Power of any domain.

Payoff

Deck

• Gemcraft Seer is mono-Mind and Nocturne is mono-Chaos, so 103.1.b.1 forces a Mind/Chaos legend. The census against data/cards.json returns four names and eight base codes: OGN-263/OGN-307 Swift Scout, SFD-199/SFD-248 Prodigal Explorer, UNL-197/UNL-234 Scorn of the Moon, VEN-151/VEN-195 Soul's Reflection.
• One rainbow Power available at the moment of the look - the play is not free, and both halves are 'you may', so a Nocturne seen with no Power simply stays where the look leaves him.

Prerequisites

• IT IS A REPLACEMENT EFFECT AND THE CATALOGUE HAS BEEN CALLING IT A TRIGGER. 370.1.b.1, cited by nothing before this entry: 'In the case of Replacement Effects that describe a game action to occur “as” an event occurs, the described event is replaced by that same event plus the game action being performed.' Its worked example is SFD-175 Undertitan, printed in this pool. So the look is not followed by Nocturne's clause; the look IS the banish and the play. 370.1.b is the general form: 'When a Replacement Effect applies, it replaces the qualifying event with one or more Game Actions or events, or the qualifying instruction with another instruction.'
• WHICH BUYS THREE THINGS A TRIGGER WOULD NOT. It never becomes a Chain Item, so it cannot be countered and there is no window between the look and the body arriving. No trigger multiplier in the pool touches it - OGN-236 Karthus doubles [Deathknell] effects, UNL-087 Blue Sentinel and UNL-029 Red Brambleback double hold and conquer triggers, and a Replacement Effect is none of those. And 371.2 is what makes the 'you may' legal: 'If the Replacement Effect says a player “may” apply the Replacement Effect, the player has the choice of whether or not to apply it.'
• 312.1.b.1 IS THE PARAGRAPH THAT LETS IT HAPPEN ON THE OPPONENT'S TURN, AND THE WHOLE OF 312.1 AND 419.1-419.2 WAS UNCITED. 419.2 says of playing a card 'This is a Discretionary Action', 312.1 says 'Priority is the singular exclusive right to take Discretionary Actions' and 312.1.b says 'If no player has Priority, no player can take Discretionary Actions' - which is the rules-text home of what this project has always derived from 312.2.a. Then 312.1.b.1: 'Players can always take and make choices for Limited Actions when instructed, regardless of Priority.' Being INSTRUCTED to play Nocturne is a Limited Action (410.2.a, 410.2.b), so it needs no priority and is not bound to your Main Phase. The catalogue cites 312.2.a 81 times and had never cited 312.1 or any of its sub-rules.
• SO THE BODY CAN LAND INSIDE THE OPPONENT'S COMBAT. Play any [Ambush] or [Reaction] unit on their turn under the Seer's static, look at the top card, find Nocturne, and 355.2.a puts him at your base or a battlefield you control - the contested one included. 319.6 with 323.2.a then give a body that becomes present mid-combat its designation at the next Cleanup, before 465.2 resolves, so a 4 Might defender appears after the attackers were declared. 143.4 makes him enter exhausted, which costs nothing on defence (neither 464.2.c.3 nor 465.2.b filters by state) and 415.3.a readies him at your own Awakening.
• 817.2.b IS THE HONEST CAP ON THE MASS GRANT: 'If the player does not recycle the top card and nothing else happens in between the triggers resolving, each instance of Vision will see the same card.' So N units played in one turn are not N cards deep - they are one look with N re-rolls, and each re-roll costs you the card you recycled (416.1 puts it on the bottom). Against a 39-card deck (103.2.a with the Chosen Champion set aside under 103.2.a.1) three Nocturnes are a real hit rate over a game and never a plan for a given turn.
• 370.2 MAKES COPIES REDUNDANCY, NOT SCALING: 'A Replacement Effect can only be applied once to an event, or to any Game Actions or events that replace that event.' A look at one card can only ever see one Nocturne, so the second and third copies raise the chance of seeing one and never the number you deploy per look.
• THE VERB IS WHY THIS WORKS AND UNDERTITAN'S DOES NOT. Nocturne says 'look at OR reveal'; SFD-175 Undertitan says only 'As I'm revealed from your deck'. 436.1 defines Predict with 'look at' and 817.1.b defines [Vision] the same way, while 424.1 makes revealing a public presentation - so [Vision] and Predict feed Nocturne and can never feed Undertitan. Nocturne is the printed exception to the project's standing 'a predict never reveals' rule.
• 431.1.c KEEPS IT SAFE IN AN EMPTY-DECK SHELL: looking and revealing past the deck do not Burn Out, and 431.1.c.1 extends that to the zone change that follows - so the recycling half of [Vision] is free where a draw would be 431.1.a.
• DISTINCT FROM nocturne-stacked-deck-cheat, which shares only Nocturne. That entry buys looks with OGN-183 Stacked Deck, a mono-Chaos [Action] spell at 1 Energy for three cards, and keeps the shell mono-Chaos; this one buys them with a static that makes every unit you play a looker, pays a second domain for it, and states the rules mechanism - the earlier entry calls the clause a trigger and cites no paragraph for it at all. The correction belongs there as well as here.
• IT DELIVERS A BODY AND SCORES NOTHING. Nocturne's [Ganking] is the only thing he does once he lands (810.1.c.3: Ganking adds destinations for the Standard Move and no extra movement), so the class is ENGINE.
• THE MONO-CHAOS TWIN IS `mystic-poro-nocturne-mono-chaos-look-package`, AND IT IS THE WEAKER HALF ON PURPOSE (back-reference added on merge, 2026-09-12). `OGN-100 Gemcraft Seer` prints *"Other friendly units have [Vision]"* - a STATIC, so this version looks through every unit you play - while three `OGN-171 Mystic Poro` are three ONE-CARD looks, modelled at about 22% against this package`s 51%. What the twin buys is not throughput but IDENTITY: the Seer is mono-Mind and forces one of four Mind/Chaos legend names, while the Poro package is mono-Chaos end to end and rides in ANY Chaos pair. Both rows now cite each other - this one was owed the link and did not carry it.
• WHY AN ABILITY ON A CARD NOBODY HAS PLAYED WORKS AT ALL, WHICH THIS FAMILY CITED FOR NEITHER (upgrade 2026-09-12, #187 batch 15). Every entry in the Undertitan/Nocturne family cites 370.1.b.1, which says what KIND of ability it is and nothing about why it is active in the Main Deck. Three paragraphs answer that: **365.1 is the DEFAULT that would kill the family** - *"Passive Abilities of Permanents are typically only active while on the Board"*; **366.1 is the OVERRIDE** - *"Passive Abilities of cards in zones that are outside of the Board will self-describe their context"* - which was cited by TWO entries out of 762, neither of them here; and **368.1** - *"Passive Abilities can be Replacement Effects"* - had ZERO citations anywhere and is the hinge, because it is what makes 366.1 rather than 385.1 the applicable block. This project carries 385.1 and 385.2, the TRIGGERED-outside-the-board pair, at 16 and 42 citations and had never had the passive counterpart, so a reader reaches for 385 and gets the wrong block. **424.1.a.2** completes it - cards remain in the zone they are being Revealed from, with Riot naming the top of the Main Deck - which is why the self-described context is satisfied at the instant the passive fires.
• 370.3 IS THE NARROWEST AND MOST ON-POINT PARAGRAPH FOR THIS CARD AND IT WAS MISSING FROM THE WHOLE FAMILY (self-audit upgrade 2026-09-12, #187 batch 20). The earlier pass prescribed 365.1, 366.1, 368.1 and 424.1.a.2, which are about PASSIVE ABILITIES IN GENERAL. **370.3 is about REPLACEMENT EFFECTS AND ZONES SPECIFICALLY**: *"If a Game Object has a Replacement Effect that is active in a specific zone, it is evaluated and subsequently applied if it enters that zone before an event occurs that it could replace."* Measured on 2026-09-12 it was cited by **exactly ONE entry in 762** and by none of this family. 366.1 says a passive outside the board self-describes its context; 370.3 says a replacement effect can be ACTIVE IN A ZONE and is applied if the object entered that zone first - and for a card sitting in the Main Deck since the game began that timing half is free, **which is exactly why it is easy to leave out** and why its worked example is the case where the half BITES.

Steps

1. Resolve a Gemcraft Seer onto the board. His own [Vision] is one look; the static is the engine.
2. Every other friendly unit you play from now on has [Vision] and looks at the top card of your Main Deck as it enters (817.1.c makes the trigger the permanent entering the Board).
3. When a look shows OGN-194 Nocturne, apply his Replacement Effect: 370.1.b.1 makes the look BE the banish and the play, with no Chain Item in between.
4. Pay one rainbow Power and put him on the board. 355.2.a sends him to your base or to a battlefield you control.
5. If the look happened on the opponent's turn - an [Ambush] or [Reaction] body under the Seer's static - 312.1.b.1 lets you take the instructed play with no Priority, and 319.6 with 323.2.a give him the Defender designation at the next Cleanup.
6. If the look does not show Nocturne, use [Vision]'s own recycle to put that card on the bottom (416.1) and let the next unit you play look again.

Per iteration

one look per unit played, and a 4 Might [Ganking] body for one rainbow Power on any look that shows Nocturne

How it ends

engine only - 370.2 allows one application per event, 103.2.b caps Nocturne at three copies, and 817.2.b makes N looks one card deep unless you spend a recycle between them

Sources

Published elsewhere

• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt) 2026-07-16

Walked here, in this project

• Hand walk 2026-09-12, uncited Core Rules sub-rules 300-499, batch 5 2026-09-12 record

Walked against Core Rules 2026-07-16

Match a deck list against the whole catalogue