Multi-day party runs with funding decisions, TwinBee-narrated floor events,
spectator parimutuel betting, basket/mimic gift system, and weighted-roll
item distribution including masterwork drops at T4-T5.
Schema (5 tables, 2 fewer than spec by computing helpfulness on-the-fly and
skipping the loot-pending state):
- coop_dungeon_runs / _members (daily funding as JSON column)
- coop_dungeon_events (votes as JSON, used to derive TwinBee helpfulness)
- coop_dungeon_bets / _gifts
Mechanics:
- 2-4 player parties, 24h invite window, locks consume one combat action
- Per-floor success roll: base + sum(funding) + level/pet bonuses + event
vote modifier + active gift modifiers, clamped to 5..95
- Funding tiers (none/min/std/agg/all_in) with liability cap at +8% for
under-leveled players
- TwinBee narrates events from existing flavor pool; 20 authored events with
per-option modifiers and embedded recommendation
- Parimutuel betting with 10% rake; odds line shown on lock/daily/status posts
- Gift modifiers symmetric at 50/50 sender mix so no dominant strategy
- Item drops on success via weight-by-contribution roll; T4 25% / T5 100%
masterwork chance (random pick from existing T4/T5 defs)
Balance via Monte Carlo (coop_dungeon_balance_test.go):
- All tiers exceed 1.5x solo daily income at average party profile
- Optimal funding strategy walks up tiers correctly (Min/Std/Std/Mixed/Agg)
- All-In stays -EV at every tier (boost lever, not optimal play)
Tests: parsing, liability cap, JSON roundtrips, vote tally with leader
tiebreak, event meta consistency, parimutuel payouts, gift EV symmetry,
weighted-roll distribution (Monte Carlo), masterwork tier gates.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>