The ambush rules are pretty straightforward but sometimes you just surprise a foe or get into a situation where one person or group has an advantage over the other. In those instances, you have a situation akin to an ambush but where the setup was accidental, unnecessary or completely visible but one side has an advantage of time to prepare. In these circumstances, you would give them one or more of the following to account for the advantage:
- Bonus to ATK. Usually a +10 to +30 bonus.
- Set CF to 40 for the melee round. Essentially gives them a "leg up" on the other person.
- Bonus to an action. Usually a +10 to +30 bonus.
Pretty much the GM gets to decide when this may apply and its very situation driven.