Ability Checks
From OSE SRD
The referee may use a character’s ability scores to determine the character’s chance of succeeding at various challenging tasks.
Rolling an Ability Check
The player must roll 1d20 and try to get equal or under the appropriate ability score. A result greater than the ability score is a failure.
Modifiers
The referee may apply modifiers to the roll, depending on the difficulty of the task: a –4 modifier for an easy task or +4 for a difficult task.
1s and 20s
A natural 1 should be treated as a success and a natural 20 treated as a failure.
