eight instances, and one body left to buff

Issue #329 (a slice of #200), 2026-10-13. 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: svellsongur-ivern-nurturer-optional-draw, the Calm ENGINE that puts three SFD-059 Svellsongur on UNL-051 Ivern, Nurturer for eight instances of his Hold trigger: every Hold looks at 24 cards, draws as many units as you like and places up to eight buffs. The entry is right that the trigger survives being multiplied, because every clause in it is optional. Walked as a game, the eight instances arrive at the start of T6, and by then the board holds one unbuffed body and the runes pay for three of the units drawn. A buff cannot reach a unit drawn by the same Hold, and a buffed unit cannot take a second one, so each Hold buffs at most the unbuffed bodies on the board when it resolves. Against an opponent removing a body a turn, four instances already cover that. The third Svellsongur costs the three bodies that would have used the buffs.

Why this line. scripts/sequence-pick.mjs --unplayed, re-run on 2026-10-13 at 34bd651, reads 771 entries, 262 with forced-ordering language, 102 in the queue and 47 of them with no play, unchanged from the issue. The pick is by global rank, skipping entries that already have a play: this entry is rank 54 (a hit on first), first in the list. The other entry of this slice is rank 56, OGS-017 Dark Child's [Repeat] tax, played in the Repeat counters only into two or three spare Energy. Svellsongur's doubling on a scoring carrier is walked in each Svellsongur is worth exactly what the board is missing.

1. Needs

The card text the play turns on:

• Ivern, Nurturer: "When you play me or when I hold, look at the top 3 cards of your Main Deck. You may reveal a unit from among them and draw it. Recycle the rest. Then if you revealed a Bird, Cat, Dog, or Poro, do this: [Buff] a friendly unit. (Give it a +1 :rb_might: buff if it doesn't have one.)"
• Svellsongur: "[Equip] :rb_energy_1::rb_rune_calm: (:rb_energy_1::rb_rune_calm:: Attach this to a unit you control.) As this is attached to a unit, copy that unit's text to this Equipment's effect text for as long as this is attached to it."
• Fire Below the Mountain: ":rb_exhaust:: [Reaction] — [Add] :rb_rune_rainbow:. Use only to play gear or use gear abilities." The rainbow pays a Calm cost, 135.2.e.5.b: "When Added to a player’s Rune Pool, [A] can be spent to pay a Power cost of any Domain." Its Chosen Champion has to carry the Ornn tag (103.2.a.2); SFD-058 Ornn, Blacksmith is idle in the walk.

2. What eight instances are, priced both ways

The entry's arithmetic stands on R6 = A (Svellsongur copies the carrier's current text) and 434.1.c: "The Top-Most card has all Effect Text of all cards Attached to it appended to its Rules Text." The first gear copies one sentence, the second copies the two that Ivern then carries, and the third copies four: 2^v instances for v gears, eight with three. Each gear doubles the count, so losing any one of them halves it.

Whether eight identical appended sentences are eight abilities or one is OQ-SVELL-CAP, which no paragraph of the Core Rules settles. As recorded it is about a capped trigger, and Ivern's carries no "each turn", so the catalogue's per-instance count is the reading this play walks. Read the other way, the gears add nothing and Ivern looks at three cards a Hold whatever v is. Everything below is per instance.

3. Where Ivern stands

His trigger reads "when I hold", so he has to be at a battlefield you control when 315.2.b.2 runs: "1. The Turn Player Holds all Battlefields they Control." He does not have to walk there. 355.2.a: "By default, Valid locations include the controller’s Base or a Battlefield the controller controls." Played to A on T3, he holds at the start of T4. Played to base, he enters exhausted (143.4: "Units enter the Board exhausted."), walks on T4 after the Hold has already happened, and first holds on T5. Walking costs one Hold.

The gear is the other way round. 148.1.a.1: "Gear can only be played to a player's Base unless an effect specifies otherwise." Svellsongur goes to base, and its [Equip] reaches Ivern at A. Its Might Bonus is +0, so the gears leave him at 4 and a buff is the only thing that moves him.

4. Their order: B, bodies, and a removal spell a turn

Fury/Chaos under SFD-185 Glorious Executioner, whose "When you win a combat, draw 1" is idle in a game with no combat. They take B on their T2 and build it, and while their bodies hold B they answer A with spells. A unit at B cannot reach A in one move: a Standard Move goes from base to a battlefield or back (144.4.a, 144.4.b). Their removal is OGN-024 Void Seeker (Fury, E3 + 1 Power): "[Action] (Play on your turn or in showdowns.) Deal 4 to a unit at a battlefield. Draw 1." Four damage kills every body here except Ivern after a buff.

5. The turns, going first

Calm/Mind against Fury/Chaos. Your rune deck is eight Calm and four Mind; nothing in the list pays Mind Power. Your opening four are Stalwart Poro, Mutated Mouser, Ivern and Svellsongur. The draws are Lonely Poro on T1 and Svellsongur on T2 and T3, so every gear is in hand before Ivern's first look: his look recycles any Svellsongur it sees, since it can draw only a unit.

turn    runes   your turn                                                 points
T1      2       Stalwart Poro (E2) to base.                               0
their T1        Shipyard Skulker (E3) to base, on the 485.7 extra rune.
T2      4       Poro walks to A, Conquer: +1. Mutated Mouser and Lonely   1
                Poro (E2 each) to A. All four spent.
their T2        Skulker walks to B, Conquer. Mystic Poro (E2) and a
                second Skulker (E3) to B. All five spent.
T3      6       Hold A: +1. Ivern (E5 + 1 Calm) played to A: five         2
                exhausted, one of them a Calm recycled. Five runes, one
                ready. His play trigger: a Poro among the top three,
                revealed and drawn, the other two recycled. Buff Ivern:
                M5. One rune idle.
their T3        Hold B. Void Seeker on Stalwart Poro at A: it dies, they
                draw 1. Traveling Merchant (E2) to B. Six runes, two
                ready.
T4      7       Hold A: +1. Ivern's Hold, one instance: a unit drawn,     3
                buff Lonely Poro (M3). Svellsongur (E3, its Calm Power
                from the legend's rainbow) and its [Equip] on Ivern (E1
                + a Calm recycled): two instances. A second Svellsongur
                (E3 + a Calm recycled) to base. All seven exhausted, two
                recycled: five runes.
their T4        Hold B. Void Seeker on Lonely Poro: it dies, they draw 1.
                A third Skulker (E3) and a second Mystic Poro (E2) to B.
                All eight spent, one Fury recycled.
T5      7       Hold A: +1. Two instances: two units drawn, but Mouser    4
                is the only unbuffed body: one buff, Mouser M2, and
                the second finds nothing. [Equip] the second
                Svellsongur (E1 + the rainbow): four instances. The
                third (E3 + a Calm recycled) and its [Equip] (E1 + a
                Calm recycled): eight. A Lonely Poro (E2) to A on the
                last two runes. All seven exhausted, two recycled: five
                runes.
their T5        Hold B. Void Seeker on Mouser: it dies, they draw 1. A
                second Traveling Merchant and a third Mystic Poro (E2
                each) to B. Two runes spare.
T6      7       Hold A: +1. Eight instances: 24 cards looked at, up to    5
                eight units drawn. One unbuffed body on the board, the
                Lonely Poro played on T5: one buff. Main Phase: three
                2-drops on seven runes.

Their points: 1 on T2, 2 on T3, 3 on T4, 4 on T5. After your T6 it is 5 to 4, the contested curve of one Hold a turn on each side: the engine scores nothing, as the entry says.

What the eight instances bought on T6 is one buff and three plays. Ivern is buffed, the buffed Mouser and Lonely Poro are dead, and the only unbuffed body is the Poro from T5. At most one of the eight buffs lands; the rest find only buffed bodies, 702.3.a: "If a Buff is added, or instructed to be added, on a Unit that already has a Buff, it is not placed instead." The same cap already bit on T5, where two instances met one unbuffed body. The units drawn wait in hand: three from T3 to T5, up to eight more on T6, and seven runes to play them.

A buff never reaches a unit the same Hold drew, unless it has [Ambush]. The Hold happens in the Beginning Phase. 310.1.a: "By default, cards can be played and abilities activated only when a player has priority on their turn in a Neutral Open state." While the instances are on the chain the turn is in a Closed State, and once the chain is empty the open-state priority is a Main Phase one, 312.2.a: "When the turn is in a Neutral Open State during their Main Phase." The exception is 822.1.b: "I have [Reaction] as long as I’m being played to a battlefield where you control Units." A drawn [Ambush] unit can be played to A between two instances and take a later one's buff; the Calm/Mind ones are UNL-071 Chakram Dancer (Mind, E3) and UNL-060 Vilemaw (Calm, E8 + 2), and this list runs neither. With no [Ambush] unit drawn, every Hold buffs at most the unbuffed bodies on the board when it resolves, and 702.3 allows one buff on a unit at a time, so a body takes one and is done. Against a removal spell a turn that is one or two bodies a Hold here.

What the third Svellsongur cost is three bodies. Its E3 + 1 and E1 + 1 on T5 are six runes, two of them recycled. Stop at two gears and the T5 Main Phase is the second [Equip] on the rainbow and three 2-drops on the six runes left, with nothing recycled. Their Void Seeker kills one of the three, and on T6 four instances meet two unbuffed bodies: two buffs where eight instances placed one, four units drawn, nine runes instead of seven, and four bodies on A instead of two. Had they killed Mouser instead, it is three buffs. The third Svellsongur stays in hand, ready to replace a gear they send back (§6).

How often this happens. The gears are the bottleneck: Ivern's look finds units and Svellsongur is a gear. The draw pile is 39 cards, the 40 of Tournament Rules 601.1.b less the Chosen Champion, which 103.2.a.1 places in the Champion Zone, and the walk needs the gears among the first seven (the opening four and the T1 to T3 draws). All three there is 0.38% of games without a mulligan; with the entry's one Ivern also among those seven it is 0.04%, and 0.12% with three Ivern. The two-gear line casts both on T4, so it needs two among the same seven: 7.7% on the gears alone, 1.06% with one Ivern and 2.84% with three. The play trigger finds a tag among the top three in 92.7% of deals here: after T3 you have seen Stalwart Poro, Mouser and Lonely Poro, so 18 of the 32 cards left are tagged.

6. Breaks to

In their colours, the line breaks to VEN-008 Ruthless Strike (Fury, E3, no Power), the cheapest Fury or Chaos spell in data/cards.json that kills a Might-5 unit at a battlefield outright: "[Action] (Play on your turn or in showdowns.) As an additional cost to play this, you may discard 1. Deal 3 to a unit at a battlefield. If you paid the additional cost, deal 5 to it instead." Ivern stands at a battlefield by construction, a buff takes him to 5 and no further, and Svellsongur adds +0. Three Energy and a card, on their T3, and the gears never have a carrier. OGN-033 Shakedown costs the same three resources and deals 6, but the choice is yours: you may let them draw two instead. Outside their colours OGN-213 Hidden Blade (Order, E2 + 1 Power) is cheaper: "Kill a unit at a battlefield. Its controller draws 2." Unbuffed, he dies to less: VEN-015 Decree of Rage (Fury, E1 + 1 Power): "[Action] (Play on your turn or in showdowns.) This can't be countered. Deal 4 to an enemy Calm (:rb_rune_calm:) unit." It reaches him in your base as well, and it is why the play trigger's first buff goes on Ivern.

Killing him does not take the gears. 719.5: "When a Top-Most Card changes zones from a board zone to a non-board zone, all Attached cards Detach from it, remaining in their current zones." Then 457.1: "When an un-attached non-Unit Gear is created or played at a battlefield, or is at a battlefield for any other reason, it is Recalled to its controller's base during the next Cleanup." The rule's own example is this case. The Svellsongurs sit in your base, and what the removal destroyed is Ivern and the [Equip] costs. Rebuilding is a second Ivern (E5 + 1) and E1 + 1 Calm for each re-attach, and with the entry's one Ivern there is no second.

Each gear breaks to SFD-135 Factory Recall (Chaos, E1): "[Action] (Play on your turn or in showdowns.) Return a gear to its owner's hand." One Energy, at Action speed, halves the instances, and replaying the gear costs you E3 + 1 and its [Equip] E1 + 1, of which the rainbow pays one Power. SFD-005 Detonate ("Kill a gear. Its controller draws 2.") takes a gear for good for two resources and pays you two cards.

7. Verdict

Right about the trigger, and the ceiling is the board, not the copy limit. Every clause in Ivern's trigger is optional, so eight instances never Burn Out and never force a draw. The play adds three things the entry does not state. With no [Ambush] unit drawn, the buffs can land only on bodies already on the board when the Hold resolves (310.1.a, 312.2.a), each takes one (702.3.a), and so a Hold buffs at most the unbuffed bodies there: one or two a turn against an opponent removing them. The draws are capped by the runes, about three plays a turn here, and two gears already draw four. The third gear's six runes buy instances with nothing to do, and spent on bodies instead they leave four instances with two buffs where eight placed one. And Ivern is the piece that breaks: Might 5 at most, at a battlefield by construction, and in Fury/Chaos VEN-008 Ruthless Strike kills him for three Energy and a card.

8. Not verified

I did not deal the channel order. The Calm Power the schedule recycles is one by T3, three by T4 and five by T5, among the first six, eight and ten runes; with eight Calm in the twelve it never fails (0 of 495 deals), and with an even six and six it fails in 210 of 924 deals, 22.7%. The two-gear line needs one, three and three, and fails in 28 of 924 deals with six Calm, 3.0%, never with eight. Their Void Seeker needs one, two and three Fury among their first seven, nine and eleven runes, which six Fury always meets. Whether eight identical appended triggers are eight abilities is OQ-SVELL-CAP, open; per ability the gears do nothing. Whether a card is a champion unit is not in the card data, so I did not price UNL-195 Green Father with Ivern as its Chosen Champion (103.2.a.2, 419.1.a), which would put him in every game at the cost of the rainbow. I did not walk SFD-058 Ornn, Blacksmith or SFD-041 Apprentice Smith digging for the gears, Ivern's Hold seeing recycled cards again once the deck is shorter than the looks, the mulligan, or 2v2. The probabilities in §5 count only gears in hand by T3: from T4 on, a draw comes after Ivern's looks, which recycle any Svellsongur among the top three to the bottom, so a gear drawn on T4 or later is outside the model, and with it the dealing of any later gear.

Leads

• The entry's step 1 reads "Play Ivern, Nurturer (E5 + 1 Calm Power) and walk him to a battlefield you control". 355.2.a plays him there directly, and the walk costs a Hold: played to base he enters exhausted (143.4) and first holds a turn later.
• The entry's fourth notable reads "Eight instances therefore place up to EIGHT buffs, one each on eight different unbuffed bodies". Those bodies have to be on the board when the Hold resolves: no unit is played in the Beginning Phase (310.1.a, 312.2.a) unless it has [Ambush] (822.1.b), so with no [Ambush] unit drawn the units the Hold draws cannot take its buffs, and 702.3.a leaves a buffed body unable to take another. Each Hold buffs at most the unbuffed bodies on the board when it resolves; on the walked board, one on T5 and one on T6.
• The entry's cost notable totals "17 Energy and 6 Calm Power". The 17 Energy includes Ivern's E5; the Calm Power leaves out his 1. With it, the line is E17 + 7 Calm Power.
• The entry's refutation (b) says "a removal spell on him erases the whole investment at once". The gears survive (719.5, then 457.1 recalls them to base); what goes is Ivern and the three [Equip] costs. In the walked opponent's Fury/Chaos, the cheapest spell that kills him outright is VEN-008 Ruthless Strike (E3 and a discard), since a buff takes him only to Might 5; in Order, OGN-213 Hidden Blade (E2 + 1 Power) does it and hands you two cards.