Some examples to help people figure stuff out.
Augmentation is when an ability is used to support or improve another ability; a portion of the rating of the augmenting ability is added to the rating in the augmented ability - typically this is 10% of the augmenting ability (an "automatic augmentation") although it is possible to get more out of the ability with a simple contest.
Example: Mirava is in a small forest near Avalon and is being pursued by three opponents armed with bows. She is not overly familiar with this particular forest and she has not spent anytime familiarising herself with the area. Readying her bow and humming her "first magic" - her Lucky Arrow Song - she prepares to skirmish with her pursuers.
The abilities used in this example are:
Archery 9m
Swiftstrike, a magical bow (+3) 18
Mithril shirt (+3) 13
Lucky Arrow Song spell 18
Skirmish Combat 20
Stealthy 20
Tough 13
Valiant 20
Mirava therefore has 7m2 (29 + 5 + 4 + 2 + 2 + 2 + 1 + 2). However, instead of taking the automatic augmentation from Skirmish Combat her player decides that Mirava will attempt to take up a better position, and have some pre-planned locations to fall back to. Mirava's player decides to try for a +3 bonus (instead of the automatic +2) and rolls against a resistance of 15, gaining a Minor Victory and the full +3 bonus. This makes Mirava's augmented Archery rating 8m2.