OpaSmash's StartGuide
I've taken the liberty of copying the post from the old forum. It's not feasible to copy the discussion that followed as it is 4 pages long. Things have moved on since this was originally publishe...
Forum Discussion
Attacking forgotten are unpredictable as far as I know. The only thing predictable is when in the base areas and you can find out if they are going to send one, two etc waves of attack.
