Attacking planets
Stages
Preparation
Fighters take out fighters
Fighters take out fighters and other items
Fighters take out fighters, and some return
No more fighters
Troops take out troops
Troops take out troops and other items
Troops take out troops, and some return
YAAAA!
Alternate scenarios
If you attack with troops while fighters are still present on the planet, the fighters will take out anywhere between 9 and 43 troops per fighter.[1]
Spies
Spies level of confidence is random number between 50 and 98.[2] For example, if the spy has a level of confidence of 75, the amount of an item reported can be anywhere between 75% of the actual amount and 125% of the actual amount.[3]