One Hero Engine: Quick Reference

Roll-under test

Roll 1d20 equal to or under the relevant Attribute.

Equal succeeds.

Difficulty

• Favourable: Advantage
• Standard: normal roll
• Difficult: effective Attribute -2
• Severe: effective Attribute -4

Effective Attribute cannot exceed 19 or fall below 1.

Advantage and Disadvantage

• Advantage: roll 2d20, keep the lower
• Disadvantage: roll 2d20, keep the higher
• They cancel
• They do not stack

Critical results

• Natural 1: critical success
• Natural 20: critical failure
• Attack natural 1: increase damage by one Step or gain an equivalent benefit
• Attack natural 20: fail and introduce a complication

Two-action turn

1. Establish range bands
2. Check surprise if needed
3. Hero takes two actions
4. Resolve attacks or casts
5. Roll damage
6. Apply Soak
7. Resolve Fray once if eligible
8. Resolve enemy turn through Defence tests
9. Test Morale when appropriate
10. End through defeat, retreat, surrender, escape, or objective completion

Guard and Threat

Damage Steps

Soak

• Damage taken = damage roll minus Soak
• Minimum damage after Soak is 0
• Fighter starting Soak 2
• Rogue starting Soak 1
• Magic User starting Soak 0
• Shield can raise Soak by 1, up to Soak 3 unless a rule says otherwise

Fray

• Levels 1-5: 1d6
• Levels 6-10: 1d8
• Trigger once each hero turn after an offensive action
• 4 or higher: defeat one eligible Minion
• 3 or lower: no effect
• Fray never defeats more than one Minion per turn

Recovery

• Short rest: about ten minutes, once per scene when possible
• Short rest healing: 1d6 HP
• Fighter short rest bonus: +2 HP
• Rogue short rest bonus: +1 HP
• Magic User short rest bonus: none
• Long rest: restore all HP, all MP, once-per-day abilities, and temporary conditions unless a rule says otherwise
• HP to MP: lose 2 HP to regain 1 MP, never below 1 HP

Defeat

• At 0 HP, the hero is Defeated
• The current scene ends against the hero unless a Trait prevents it
• The hero returns with 1 HP once the immediate consequence is resolved
• Death happens only by player choice or a second Defeat before a long rest when no other outcome fits

Oracle

1. Roll one Chance die and one Risk die
2. Add one extra Chance die for meaningful advantage
3. Add one extra Risk die for meaningful danger
4. Keep the highest Chance die
5. Keep the highest Risk die
6. Compare

• Chance higher: Yes
• Risk higher: No
• Equal: Yes, but; increase Twist by 1

Winning die 1-3 = But

Winning die 4-6 = And

Twist

• Track Twist from 0 to 3
• At 3, introduce a major complication
• Reset Twist to 0

Enemy ranks

Resolve targets:

• Unsteady 6
• Trained 11
• Fanatical 16

Session loop

• Begin with Objective, Threat, Stakes, and one opening Oracle question
• Play two or three scenes
• End by recording Outcome, Cost, and Thread