Initiative (init)
We know from the Resolve skill that initiative (init) is a trait that evolves from it:
init -> chk= +M(Resolve)
Players roll for their own character, the GM usually rolls a single check for the creatures they are controlling (see below). The order of turns for each round of the contest, then goes from the highest init score to the lowest. The initiative order remains the same in each round, until the contest is resolved. If a tie occurs in the initiative order, it is the creature with the higher Modifier (M) on Resolve that goes first. If this is still a tie, then the compare Modifier (M) on Perception, if this still doesn’t resolve it then you can just do another d20 roll or just decide arbitrarily.
GM Notes on Initiative
Rolling for each of the character's foes can be time-conduming and fiddly, especially when they're facing the crime boss' private army. There are a few approaches that can help here.
One way is to put the foes into groups by init. The lightning quick assassins can all be grouped under your best roll, the boss might get another, while the rest of the "soldiers" get the third. If init varies amongst the members of the group, just take their average when making the roll. If a member has an init, which is really different to the rest, consider putting them into thier own separate group.
The other way is just roll once for all of them, using their average init. This is quick, but can be a bit unrealistic.
As the GM, this is all up to your discretion.