A successful roll that is also a double (e.g. 11, 22) is a “Critical” and the protagonist concerned receives some extra benefit. This might mean that the task is performed particularly well or quickly, or that it brings some additional (but related) benefit. In combat, this typically means inflicting additional damage or causing an opponent to drop their weapon (see Chapter 4). Non-combat examples might include a critical Influence roll leading to the target divulging additional important information, or a critical Arcane roll leading to a spell’s effects being magnified in terms of its range, duration or power.
Conversely, a failed roll that is also a double (e.g. 99, 00) is a “Fumble” and something has gone badly wrong. Weapons are dropped, bowstrings are snapped, unintended offence is caused, or tasks generally take longer or are performed more noisily.
For both Criticals and Fumbles, players should be encouraged to offer suggestions as to the nature of the spectacular success or failure, but, as always, the Referee’s decision on such matters is final.