Complications
Splitting allows you to do two things in one segment. However, it
becomes correspondingly harder. The first action is at +1 and the
second at +2 difficulty
eg: Tom splits his pool evenly, 2 into each action. He swings a
punch at difficulty 6 (5 + 1) and then tries to dodge a blow
at diff 8 (6 + 2).
You can avoid this added difficulty by spliting over two segments.
eg: tom has rolled an initiative of 3. He splits his actions as
above, but opts to punch on 3 and dodge on 1. Both actions are at
the standard difficulty, and still roll 2 dice in each.
Combined with rage, this can make you a combat nightmare.
eg: Vilna the Umbral Ahroun has a dex of 4 (5 in crinos)
and a brawl of 3. He has a wits of 4.
He rolls 9 on the initiative. He spends a point of rage, and
thus has 5 actions. He goes on 9, 7, 5, 3 and 1. He opts to
split each action down a segment. He now has an action on
9,8,7,6,5,4,3,2,1 and 0, each rolling 4 dice.
Any resulting dice roll is made at the full number of dice - if any of Vilna's blows connects, he rolls full strength, not split for damage.
Any action may be split in order to take two actions at once, not just combat actions. The only disadvantage is having less dice for each action