Success rolls are the core mechanic for resolving actions in Hexidecimate. You roll a D20 and add your modifiers to try to reach the target number.
Target Number
The base target number for success is 16 or higher on a D20. This applies to attacks and checks alike.
Success rolls are used when failure matters: attacks, persuasion under pressure, unstable movement, urgent searching, and other tasks where time, risk, or opposition makes the result uncertain.
Difficulty Modifiers
The GM can apply a modifier based on how difficult the task is before character bonuses are added.
| Difficulty | Modifier |
| Easy | Automatic success |
| Moderately difficult with no consequence for failure | Automatic success |
| Somewhat difficult | +6 |
| Moderately difficult | +4 |
| Challenging | +2 |
| Difficult | +0 |
| Extremely difficult | -2 |
| Highly impracticable, almost impossible | -4 |
| Only the legendary would attempt | -6 |
| Impossible | Cannot be achieved |
Circumstances can shift the roll further. Darkness, rain, background noise, cover, concealment, obvious tracks, loud targets, or prior knowledge of where something is can all apply situational bonuses or penalties.
The Six Checks
There are six different types of checks:
- Steadfast (SDF) - Melee attacks, holding ground, resisting fear
- Agility (AGL) - Ranged attacks, dodging, acrobatics
- Constitution (CON) - Endurance, poison resistance, physical toughness
- Magic (MAG) - Casting spells and incantations
- Will (WIL) - Mental resistance, concentration, social influence
- Life (LIF) - Survival checks, death saves, resisting wounds
Critical Success
A critical success occurs when the natural die roll is the exact number needed to reach the target number.
On attacks, this is a critical hit. It bypasses armour and cannot be deflected except by a critical deflect.
Critical Miss (Natural 1)
A natural 1 on an attack requires a Steadfast check. If you fail, you suffer a critical miss effect - you may drop your weapon, strike an ally, or otherwise fumble.
Failure
If you fail a success roll, the GM may allow another attempt at -6. If that second attempt fails, it becomes a critical failure.
If you fail by 5 or less, the GM may allow success at a cost. The cost should fit the situation: lost time, dropped equipment, a worse position, injury, unwanted attention, damaged tools, or a partial version of what the character wanted.
Telling Blow (Natural 20)
A natural 20 is a telling blow. On attacks, this deals enhanced damage and ignores the resistant condition.
Deflection
When struck, the target can attempt to Deflect, usually needing a 20! If they successfully deflect, the attack does no damage (or half damage if deflecting from a large opponent).
Contested Rolls
When two characters are in direct competition, both roll and the higher result wins. Ties may go to the defender or require a re-roll, depending on the situation.