20/+1

20/+1, or simply 20/1, is shorthand for a weapon, shield, or focus item that gives the wielder a 20% chance of +1  during skill usage. This modification can apply to any attribute for any profession, and it is not unusual for the item and increased attribute to be completely unrelated - for example, a shield with a 20% chance of +1 Earth Magic. See the Weapon upgrade article for more details on which items can carry which bonuses.