gogobee/sim_results/j2a_findings.md

J2a — autoResolveCombat cast+consume picker (verification sweep)

Date: 2026-05-17 Corpus: sim_results/j2a_traces.jsonl — 240 runs (6 classes × {manor_blackspire, underdark} × L12 × n=20) Pre-state corpus: sim_results/j2_traces.jsonl (same shape, picker disabled). See j2_findings.md for the strawman diagnosis that motivated this fix.

What J2a shipped

• internal/plugin/expedition_sim.go:
  • New simPickCombatAction(uid, sess) decision tree:
    1. HP < 40% MaxHP + heal consumable in inventory → !consume <heal>
    2. Caster with a usable damage spell (slot or cantrip) → !cast <spell>
    3. Otherwise → !attack
  • New simPickSpell(c, uid) ranks prepared damage-effect spells by slot level (descending) then expected damage from the dice string. Reaction-cast spells excluded; non-cantrips require an available slot at their native level (no upcasting in v1).
  • BuildCharacter now calls ensureSpellsForCharacter so the synthetic spellbook is populated (prod players hit this on character creation; the sim path skipped it).
  • autoResolveCombat dispatches via the picker instead of always swinging.

Built on top of the per-round -trace plumbing landed earlier in J2 (SimCombatSummary.Events, SetSimIncludeTrace).

Verification (n=20 per cell, L12 only — same cells as j2_findings)

class	zone	n	reachBoss	won	lost	rnd	pDmg	eDmg	slotRuns	casts	consumeRuns	eHP@loss
mage	manor_blackspire	20	15	12	3	7.2	133.0	74.3	15 / 15	93	12	83.3
mage	underdark	20	8	3	5	7.0	143.8	78.6	8 / 8	54	2	34.2
cleric	manor_blackspire	20	6	2	4	11.3	101.3	146.2	6 / 6	58	5	64.8
cleric	underdark	20	4	0	4	7.0	74.5	89.5	4 / 4	28	0	87.5
sorcerer	manor_blackspire	20	13	9	4	8.0	130.9	87.3	13 / 13	91	8	53.2
sorcerer	underdark	20	7	1	6	5.9	89.6	67.4	7 / 7	40	1	86.2
warlock	manor_blackspire	20	12	6	6	13.2	131.0	140.6	12 / 12	141	9	45.5
warlock	underdark	20	15	0	15	6.8	74.3	82.5	15 / 15	101	1	87.7
bard	manor_blackspire	20	12	0	12	10.6	68.1	128.2	12 / 12	117	6	75.9
bard	underdark	20	12	0	12	11.2	74.3	108.8	12 / 12	132	2	87.7
druid	manor_blackspire	20	15	14	1	6.9	142.6	84.5	15 / 15	87	11	79.0
druid	underdark	20	18	3	15	5.1	123.3	82.3	18 / 18	85	5	47.5

slotRuns = boss fights where ≥1 spell_cast fired. casts = total spell_cast events. consumeRuns = fights with ≥1 use_consumable. eHP@loss = mean enemy HP remaining when player lost.

DoD check

• J2a DoD: ≥80% of boss fights produce a cast or consumable use. MET — every cell shows slotRuns == reachBoss (100% cast rate).
• Manor mean clear (5 trailer casters): mage 60%, sorcerer 45%, warlock 30%, bard 0%, cleric 10%. Mage and sorcerer clear the ≥40% J2 target on the strength of the sim fix alone; warlock/cleric are close, bard is the one outlier still at zero.
• Druid jumped 0% → 70% manor / 0% → 15% underdark. Pre-J2a it was the lone mid-band class on weapon-attack alone; with cast on top, druid pulls into the top tier.

What's still broken and why

• Bard 0% clear despite firing 117 casts/cell. Bard's prepared damage spell registry is thin: vicious_mockery cantrip (4d4 at L11) and shatter L2 (3d8) are the only damage-effect options in defaultKnownSpells. Every other bard spell is control/buff/heal, which the v1 picker skips. Bard's average pDmg 68 in 11-round fights = 6/round — that's accurate for the spell pool, not a picker bug. Fix candidates: (a) extend bard's default known-spell list with a damage L3+; (b) widen picker to score EffectControl (hold_person, hypnotic_pattern) which trivializes enemy turns and effectively converts to damage by buying free player rounds; (c) include healing spells in the consume-priority path. (b) has the highest expected ROI and lifts cleric and warlock too.
• Cleric still bottom-of-table. 10% manor / 0% underdark. Cleric's damage-effect spells: sacred_flame cantrip (4d8 at L11) — that's it. Same shape problem as bard. spiritual_weapon, bless, guiding_bolt, cure_wounds aren't reachable by the v1 picker. Fix: same as bard — score control spells and recognise heal spells as alternatives to consumables (cleric has 40-HP healing word at low slot cost).
• Warlock underdark 0%. Different shape: high cast rate (101 casts/15 fights = 7/round), high player damage (74), but loses anyway because enemy damage averaged 82.5 and warlock has no defensive lever. Underdark boss is dropping warlock before warlock can drop it. This is a class-balance problem the post-J2b corpus needs to confirm before we move on.

Implications for J2b (the big re-baseline)

A full n=100 all-classes baseline (sim_results/baseline_j2a_all10.jsonl) is kicked off; that replaces baseline_j1_all10.jsonl as the canonical post-fix corpus. Expected shape:

• Mage / sorcerer / druid pull into mid-band (40–70% L12 clear range).
• Bard / cleric stay at bottom, but the reason is a thin damage-spell pool, not a sim artifact.
• Warlock somewhere middle; partial-clear depending on zone.
• Martials should be unchanged (picker is a no-op for non-casters with no low-HP heal trigger).

If that picture holds, the right J2 follow-up is picker widening (control + heal scoring) rather than per-class balance riders. Cleaner than five class buffs.

Files touched

• internal/plugin/expedition_sim.go — picker, BuildCharacter spell-seed, dispatch in autoResolveCombat.
• cmd/expedition-sim/main.go — already had -trace from earlier in J2.

No prod paths changed. The fix is sim-scoped.