Rulesets, Tag-Team & Kameo Assists

Ruleset feel, team structure, and assist behavior compose through explicit data instead of conditionals scattered through the shared combat core. Each combination still requires deterministic and balance validation.

V2's headline promise is not "blend every fighting game into one soup" but per-ruleset feel: when a match runs the MK ruleset it must hit like Mortal Kombat, when it runs the Tekken ruleset it must move like Tekken, and the engine underneath has to honour both from one shared roster, one shared move grammar, and one deterministic simulation. That is a harder bar than a roster crossover — it means the same fighter actor is re-skinned, frame by frame, into whichever family the match selected, by which combat layers turn on, which defensive options are legal, which super gates apply, how impacts freeze the screen, and what the decisive moment looks like. This page covers the three features that deliver that promise at the edges of moment-to-moment combat: the per-ruleset feel system and how it is tuned, the tag-team formats and mechanics, and the MK1-style Kameo assist partner. It is the feature-side companion to the "Combat & Game Feel" group; the section hub is ../V2_features.md.

What ships, honestly#

The three features sit at very different points on the implemented-versus-spec spectrum, and this page labels each one where it actually is.

• Per-ruleset feel is real and tested. The ruleset identity (EV2ShaktiRulesetId, eight families), the combat layers that activate per ruleset (GetNativeCombatLayerMaskForRuleset, a real bitmask switch), the defensive options legal per ruleset (GetNativeDefenseOptionMaskForRuleset), the nine ruleset super abilities, the per-ruleset match-flow nodes, the per-ruleset HUD overlay, and the per-ruleset game-feel profiles + balance CSVs are all substantive Unreal C++ and on-disk data, exercised by the automation suite.
• Tag-team is split. The named mechanics — Snapback, DHC, X-Factor/Pandora, Cross Assault, Baroque/Duo cancel — are not GAS ability subclasses. They are a validated data-contract catalog (FV2TagTeamMechanicsCatalog) in the V2Modes module, plus a real runtime seam on the ability system: a replicated tag-out/tag-in animation handshake and a replicated assist cooldown. Treat "each mechanic is its own ability" as aspirational; the catalog that describes them, and the handshake/cooldown plumbing they will ride, are what exists today.
• Kameo is authored data behind a launch gate. The Kameo partner system is a validated configuration inside the Create-a-Moveset editor catalog, with a default-builder and a contract test — but there is no dedicated runtime Kameo summon / health-depletion component; it shares the assist-call seam conceptually and is tracked as the launch readiness gate Gate.MK1KameoSystem.

The deterministic-combat and rollback internals these features lean on are documented in ../architecture/combat-system-gas-frame-data-and-determinism.md and ../architecture/rollback-netcode-and-tag-team.md; this page stays on the feature surface and only dips into the C++ where a claim needs backing.

Per-ruleset feel: one engine, eight families#

The ruleset identity and the layers that turn on#

A match's family is a single enum. EV2ShaktiRulesetId (V2/ue/Source/V2Combat/Public/V2CombatTypes.h:211) names eight rulesets — MK, SF, KOF, Tekken, WWE, UFC, SC, DJ — and the authored gameplay-tag table (V2/ue/Config/Tags/V2.GameplayTags.ini) carries the matching Rules.Mode.* roots (MK, SF, Tekken, WWE, UFC, SoulCalibur, DefJam, plus TagTeam). KOF is honestly a second-class citizen at the tag level — it has no Rules.Mode.KOF tag and instead surfaces through the combat-layer and tag-team mechanics — which matches the source's "seven first-class rulesets plus crossover" framing.

The actual per-ruleset feel is encoded in which combat layers activate. EV2CombatRulesetLayer (V2CombatRulesetData.h) is a 16-value bitflag set — Block, Juggle, DefenseOptions, ComboScaling, TekkenMovement, TekkenHeat, TekkenRage, TekkenPowerCrush, TekkenStance, WakeupOptions, KrushingBlow, FastCancel, ModeCancel, RingOut, Submission, EnvironmentFinisher — and UV2CombatRulesetData::GetNativeCombatLayerMaskForRuleset (V2CombatRulesetData.cpp) is a literal switch that returns the active mask per family over a CommonStrikingMask of Block | Juggle | DefenseOptions | ComboScaling | WakeupOptions:

That table is the feel difference, in code. Wrestling and MMA drop Juggle because real grappling has no air-juggle culture and add Submission; Tekken turns on its entire signature family; Soul Calibur adds RingOut; Def Jam keeps environmental finishers but drops formal wake-up option-selects. A designer can union extra layers on top via an OverrideLayerMask, and FV2CombatRulesetSelectionResult reports NativeLayerMask, OverrideLayerMask, ActiveLayerMask, and an accept/reject ReasonTag; IsLayerActive(Layer) answers per layer. The V2.Combat.Module automation spec (V2/ue/Source/V2Tests/Automation/Combat.Module.spec.cpp:213) drives GetResolvedCombatLayerMask() and asserts the per-ruleset layers (e.g. TekkenHeat, RingOut, Submission) are present or absent as designed, and that disabling bRingOutEnabled removes the RingOut layer.

The defensive grammar shifts per family#

Each family also plays in a different defensive language. GetNativeDefenseOptionMaskForRuleset maps the ruleset to its legal options from the broader defensive library:

So a Street Fighter match grants the parry, a King of Fighters match grants just-defend plus guard-cancel plus the anti-turtle negative penalty, and a Tekken match grants the instant-block timing — each from one shared library, gated by the ruleset. The full defensive vocabulary and the game-feel layer are detailed in ./combat-systems-defense-and-game-feel.md.

Per-ruleset supers and finisher gates#

Where most fighting games have one super button, V2's super is a typed family. UV2_Ability_Super (V2/ue/Source/V2Gameplay/Public/Abilities/V2_AbilityClasses.h:174) carries two real config blocks — ConfigureSuperMeterProfile(...) and ConfigureMKStaminaProfile(...) — and nine concrete ruleset variants descend from it, each configured in its constructor (V2_AbilityClasses.cpp):

The MK Fatal Blow's "only when you're under 30 % health" rule is a real FatalBlowHealthThresholdPct = 0.30f gate, not a comment — exactly the kind of ruleset-specific constant that distinguishes real feel from a renamed CRUD struct. Notice the asymmetry: WWE and UFC have no super subclass at all. Their decisive moment is not a meter-burn super but a match-flow interlude — a pin or a scorecard — which is the next layer.

Per-ruleset match flow and KO conditions#

The match-state machine injects per-mode nodes rather than baking modes into the phase enum. EV2MatchModeStateNodeType (V2/ue/Source/V2Gameplay/Public/Match/V2_MatchState.h:18) enumerates the per-ruleset interludes — MKFinisherWindow, WWEPin, WWESubmission, UFCRoundEndScorecard, SCRingOutTermination, DJEnvironmentFinisherPrompt, SFKOReplay, TekkenRageActivationLockout — each a FV2MatchModeStateNode with a duration and a bBlocksFighterInput flag, so the engine honestly stops accepting fighter input during a WWE pin mini-game or a UFC scorecard. The decisive condition itself is EV2MatchRulesetKOBehavior (TraditionalRounds, LastManStanding, FlashKO, TechnicalKnockout, SubmissionOnly, RingOutLoss), and EV2MatchRulesetStipulationType carries the WWE/SC stipulation grammar (DQOnWeapon, NoDisqualification, SubmissionOnly, TableMatch, CageMatch, RingOut, EnvironmentalFinishers). The phase machine and its rollback-safe snapshot are covered in ../architecture/combat-system-gas-frame-data-and-determinism.md.

How the feel is tuned — the data in V2/balance/feel#

The numbers that make each ruleset hit differently are deliberately data, not hard-coded C++. V2/balance/feel/hitstop_curves.csv carries a ruleset_id column and one row per family/tier — MK.Small freezes the attacker 3 frames and defender 4; MK.Heavy jumps to 8/10 with a 6-frame sakkin; SF6.Heavy stays conservative at 6/7; Tekken.Heavy sits at 7/8; SC.WeaponClash at 7/9; UFC.KO realistic at 4/6; WWE.Explosion broadcast-loud at 9/11 — and every row sets rollback_budget_excluded = true so hitstop never blows the resimulation budget. slowmo_freeze_curves.csv is likewise per-ruleset (SC.ReversalEdge 18 frames, MK.MidComboLauncher 10, WWE.BroadcastKO 54, UFC.RealisticFlashKO 30), and camera_shake_curves.csv scales from Small (0.20, reduced-motion 0.12) up to Fatality (1.20, 0.35). The per-ruleset camera-shake personality is EV2GameFeelRulesetProfileKind (MK, SF6, Tekken, SoulCalibur, UFC, WWE); GameFeelTuning.spec.cpp asserts HasRequiredRulesetProfiles() and that each profile (MK, SF6, UFC, WWE) is discoverable, and that the catalog's tunability paths point at the canonical V2/balance/feel/*.csv.

Two more pieces complete the per-ruleset surface. Individual moves resolve differently per family — UV2MoveFrameData exposes CanTekkenLaunch(EV2ShaktiRulesetId), ResolveTekkenHeatMove(...), and GetResolvedChipDamageOnBlock(EV2ShaktiRulesetId), all keyed on the ruleset (MoveDataAsset.spec.cpp). And the HUD follows: UV2RulesetHUDOverlayWidget (V2/ue/Source/V2UI/Public/V2RulesetHUDOverlayWidget.h) configures from a FV2RulesetHUDOverlaySpec, exposes GetRulesetId() and HasMeterKind(...), and swaps the on-screen meters (Drive bars, stun, rage, Heat) to match the active family. Presentation and HUD detail live in ./roster-presentation-and-stages.md.

Tag-team: formats, mechanics, and the honest seam#

Data catalog vs. runtime GAS#

The monolith says Snapback/DHC/X-Factor/Cross Assault "are abilities in V2Gameplay with their own GAS subclass." They are not. A search of V2Gameplay finds no UGameplayAbility subclass for any of them; the names resolve to a deterministic data-contract catalog, FV2TagTeamMechanicsCatalog (V2/ue/Source/V2Modes/Public/V2ModeTypes.h:4514), validated by V2.Modes.TagTeamMechanics.AssetContract (V2/ue/Source/V2Tests/Private/Modes/TagTeamMechanics.spec.cpp).

What is real runtime GAS is the seam the mechanics will ride. The ability system component carries a replicated tag animation handshake, FV2TagTeamAnimationHandshake (V2/ue/Source/V2Gameplay/Public/V2AbilitySystemComponent.h:21), a server-authoritative state machine over EV2TagTeamAnimationHandshakePhase (None → TagOutRequested → TagOutMontageStarted → TagInMontageStarted → Completed, or Rejected) with default montages AM_V2_TagOut / AM_V2_TagIn; and a replicated assist cooldown, FV2AssistCallCooldown, with CooldownFrames = 360. There is also a concrete UV2_Ability_AssistCall ability (V2_AbilityClasses.h:158, DefaultCooldownFrames = 360). And the whole thing rides the same rollback session as 1v1 — just with more fighters per snapshot — per ../architecture/rollback-netcode-and-tag-team.md.

Three formats#

EV2TagTeamFormatKind is TwoVsTwo, ThreeVsThree, Trinity, each a FV2TagTeamFormatSpec:

The test asserts each format is discoverable with the right FightersPerTeam, that 2v2 switches mid-combo and keeps one active fighter per side, and that Trinity carries the once-per-match anchor assist.

The seven mechanics#

EV2TagTeamMechanicKind carries seven entries, each a FV2TagTeamMechanicSpec of typed boolean intent plus MeterCost / CooldownFrames:

These are spec flags, not abilities — but they are checked spec: the assist cooldown is asserted to be exactly 360 frames, DHC and Cross Assault are asserted to cost meter, and Snapback is asserted to both force the opponent out and recover the snapped-out fighter's HP off-screen.

Team HP, sim, authoring, and queues#

The rest of the catalog is equally concrete. FV2TagTeamTeamHpSpec gives per-fighter bars, partner HP on the HUD, off-screen regen at 0.35 %/s (OffscreenRegenPercentPerSecond = 0.35f), and team-KO only when the entire roster is at zero HP. FV2TagTeamNetSimSpec pins SimulationHz = 60 with 2 active sim fighters per side, deterministic tag transitions, frame-accurate tag animation, and a replay encoder that records tag actions. FV2TagTeamAuthoringSpec points at real CSVs on disk: V2/balance/tag/tag_cancel_dhc_matrix.csv (per-fighter pairing rows with cross_ip_restriction and cinematic_restriction columns — e.g. Fighter.NyxRiver × Fighter.BishopCrowe is CrossIPRestricted) and V2/balance/tag/team_theme_music.csv (per-team loop/stinger cues with kof_style / mvc_style flags). Three online queues round it out — RankedTagTeam (4 players, role-preference balancing), TagCoop, and CrewBattle (best-of-five single-elimination, 6 players). The registry round-trip is verified too: UV2ModeRegistrySubsystem accepts the catalog and CaptureRegistrySnapshot reports 3 formats / 7 mechanics / 3 queues plus per-area readiness flags.

Kameo assists: an MK1-style partner, authored as data#

V2 ships a Kameo option distinct from full Tag — a second fighter who stays off-screen except during assist animations. In code it is authored configuration inside the Create-a-Moveset editor catalog (V2/ue/Source/V2Combat/Public/V2MovesetData.h), three nested structs:

• FV2KameoAssistActionDefinition — ActionId, ButtonSlotId, DirectionalModifierId, MoveId, CooldownFrames, MeterCost, with IsValidAction().
• FV2KameoFighterDefinition — KameoFighterId, an array of assist actions, HealthMax = 100, and HealthRefillPerSecond = 8.0 (the refills-while-un-summoned rule), with IsValidKameoFighter().
• FV2KameoSystemConfig — bPerRulesetToggle, bSingleSummonPartner, bDistinctFromFullTag, LaunchRulesetId = "Ruleset.MK", bCrossOverRulesetsOptIn, bRankedKameoAndNoKameoQueues, and the fighter list, with IsValidConfig().

The default builder (V2MovesetData.cpp:777) constructs an Asha Kameo by looping 3 button slots (Kameo1/2/3) × 4 directional modifiers (Neutral/Forward/Back/Down) = 12 assist actions, each with a 240-frame cooldown and 0.5 meter cost. (Worth flagging the nuance honestly: the source prose says "3 button-mapped Kameo assists," and there are indeed 3 button slots — but with directional modifiers the catalog enumerates twelve distinct assist actions, and the contract test V2/ue/Source/V2Tests/Private/Combat/MovesetDataAsset.spec.cpp:238 asserts AssistActions.Num() >= 12, that LaunchRulesetId == "Ruleset.MK", that the system is bDistinctFromFullTag, and that the ranked Kameo/no-Kameo queue split is on.) The "Ruleset.MK" id is a legacy gameplay-tag name that DefaultEngine.ini redirects to Rules.Mode.MK.

The honest caveat: this is authored data plus validation, not a runtime system. A grep for kameo across V2/ue/Source finds it only in the moveset data asset, the test harness, and the contract spec — there is no runtime component that summons the partner, drains its health when it is hit during an assist, or refills it on a timer. Those behaviours are described by the config (HealthMax, HealthRefillPerSecond, the per-action cooldown/meter cost) and would reuse the same assist-call seam the ASC already exposes (FV2AssistCallCooldown, UV2_Ability_AssistCall), but the Kameo-specific runtime is not built; the feature is tracked as the launch readiness gate Gate.MK1KameoSystem in V2/balance/launch/launch-readiness.json. So Kameo today is a fully-specified, test-backed contract — enabled in the MK ruleset at launch, opt-in for crossover rulesets, with its own ranked queue split — awaiting the runtime that consumes it.

How it connects#

Per-ruleset feel is the configuration layer over the deterministic combat core: the layer mask, defensive options, super gates, and game-feel catalog all read from V2Combat / V2Gameplay and are proven by the combat automation suite (../architecture/combat-system-gas-frame-data-and-determinism.md). Tag-team rides the rollback session and its multi-fighter snapshot, and its named mechanics are a V2Modes catalog rather than abilities (../architecture/rollback-netcode-and-tag-team.md). The defensive grammar and game-feel tuning continue in ./combat-systems-defense-and-game-feel.md; the per-ruleset HUD overlay, team theme music, and stage rules surface in ./roster-presentation-and-stages.md. The section hub is ../V2_features.md.

Related#

• Combat Systems, Defense & Game Feel — the layered combat, defensive vocabulary, and hitstop/shake/slow-mo this page configures per ruleset
• Roster, Presentation & Stages — the per-ruleset HUD overlay, team theme music, and stage/ring-out rules
• Combat System: GAS, Frame Data & Determinism — the ruleset-aware move contract, super abilities, and match-state machine in C++
• Rollback Netcode, Client-Server & Tag-Team Sim — the tag-team mechanics catalog correction and the multi-fighter rollback it rides
• The section hub: ../V2_features.md