# Concordia 3D Gate 2 — Causeway combat foundation

Entry: `/concordia/index.html?mode=3d`, linked from the existing title screen.

One live Ashbound Sentinel encounter with chasing, locked attack direction, red ground telegraphs, close-range Strike combo animation, ranged Black Flame, dodge movement and brief invulnerability, health/will displays, cooldowns, impacts, sound toggle, defeat/victory, pause and deterministic restart. Keyboard: WASD, Shift, J strike, K Black Flame, Space dodge, R restart, Escape pause. Phones use the simultaneous joystick, orbit drag and four action buttons.

## Shared rules and boundary

The runtime reads Ashen/Sentinel units through existing `fromChar`, uses the original `hitDamage`, element multipliers, `SKILLS.blackFlame`, `SKILLS.emberBolt`, `SKILLS.shieldBash`, and seeded RNG helpers. Damage, defense, HP, MP, and existing skill accuracy are not retuned. A new free basic Strike specification uses the shared damage math. The three-hit combo varies its animation, not its damage multiplier.

The adapter is a separate fixed-60-Hz real-time scheduler, not a wrapper around tactical `resolveSkill`/`enemyAct`. It replaces turn cadence only within this isolated arena. Sentinel selection is explicit: Shield Bash within melee range, Ember Bolt otherwise. This is spatial AI for Gate 2, not a claim that the historical Phase 8D ranking suite has been reproduced. Range/aim/evade checks precede seeded hit resolution; the same seed and tick-stamped inputs reproduce the same state. Attack MP is charged once at windup. Cooldowns and telegraphs use simulation ticks. Two simultaneous impacts commit before terminal evaluation, with defeat taking precedence if both die.

Unimplemented skill effects, unauthorized skills and invalid/dead targets fail closed. The supported skills have no status effects. Future skills, boss phases and world laws need explicit integration before activation; they are not silently approximated here.

Narrative, tactical combat source, Codex, progression, and save serialization remain unchanged. This encounter neither reads nor writes campaign progress or rewards. Restart resets the isolated encounter with the same seed. The existing offline shell includes the updated chunks.

## Gate evidence

Tests cover shared damage equivalence, seeded replay across 30/60/120 render rates, input immutability, cooldown/MP spam resistance, range and frozen aim, dodge timing, simultaneous-elimination defeat, terminal preemption, victory and defeat, scene teardown and unchanged game-store identity. Existing repository tests and production build must pass before publication.

Gate 3 remains the boss/phase encounter and richer character animation. Final realistic rigged character assets remain a later art integration. Real iPhone performance and browser visual QA are not certified by headless state tests.