If the ability generates a lasting effect, the duration of the effect of this ability is specified per full turn of the table.
Example:
Poisoned arrow (C - MA - Physical - DEX - 20m): The character coats his arrow with a deadly poison before shooting. The attack benefits from a +2 damage bonus. In addition, the target is poisoned for 3 turns and suffers poison damage at the start of each turn. To determine this poison damage, roll a 6-sided die (1d6) each turn of the table.