From the update:
We've had a couple novella updates so this week is going to be short and sweet. Well, actually its going to be tough and a little stinky. Yes, that's right it's—TROLL TIME!
It has been a little while since we did an arcade gang preview so lets start with a quick refresher.
Gangs are not static groups. Instead at the beginning of each command an elite model checks to see if there are any models from its gang within 2 squares of it.
If there is not it uses its solo attributes (first yellow flag), and it may only use its own abilities and unique actions.
If a member of its gang is within 2 squares of it, the gang attributes (second red flag), and it may use its bonded monster's abilities and unique actions in addition to its own.
When performing a command only elites perform actions. Minions do not perform actions. Instead minions lend their abilities to the elite.
When an elite suffers damage it checks to see if it is in a gang. If it is, the wound is placed on a bonded minion in the gang instead of taking the wound itself.