Initiative:
Initiative is what determines who acts first in combat, or encounter situation.
When a party encounters another group of creatures, each character will roll initiative against the entire encounter.
The entire encounter can be rolled as if one creature to avoid inner mixed turns that might confuse the G.M. (although it is up to the G.M. on how he or she wishes to do it).
Rolling initiative:
Roll your percentage dice (D-100) and simply add your coordination to the roll (the highest roll will be the quickest to react).
If two out of four characters beat an encounter on the initiative, those two will get the first turn to act as the others prepare to defend against the encounter. This also applies to the creatures encountered if rolling separate initiatives for each of them.
Example:
If you have a 25 coordination, you will add +25 on the % roll (1-D100). If you roll a 78, it would increase 25 points (your initiative roll would be 78 + 25 = 103.