The one-life rule
Hardcore grants +1 item if your party clears. If every player dies, no loot. Solo Hardcore on Easy is the only configuration where this is consistently profitable.
Stack the right game passes
Extra Item! gives +2 in Hardcore. VIP and 2x Gold stack with Hardcore (no penalty). The bundle that maximizes Hardcore payout is VIP + 2x Gold + Extra Item!.
Party composition
A Healer + Tank + 2 DPS group has the highest Hardcore survival rate. Mage-only or Warrior-only parties wipe ~3× more often per community reports.
Use Tool 5 before toggling
P_clear from Tool 4 (Difficulty Recommender) feeds directly into Tool 5 (Hardcore EV). At P_clear >= 0.5, Hardcore is typically positive EV. Below 0.3, stick with Normal.