See also: Character Combat
In every round during combat, each combatant gets to do something. The combatants' Initiative checks determine the order in which they act, from highest to lowest.
At the start of a battle, each player makes an Initiative skill check for their character. (A character can make an Initiative check Untrained.) The GM rolls Initiative checks for the opponents. All combatants act in order, from the highest Initiative check result to the lowest. A character's Initiative count remains the same for all rounds of the combat unless a character takes an Action that causes their place in the Initiative Order to change (See Special Initiative Actions).
The GM should write the names of the characters on a piece of scrap paper in Initiative order. That way, in subsequent rounds the GM can move quickly from one character to the next. If two combatants have the same Initiative check result, the character with the highest Initiative check modifier acts first. If there is still a tie, roll an additional Initiative check to determine between the two as to which character goes before the other. To save time, the GM can make a single Initiative check for all of the opponents, rolling 1d20 and adding the lowest Initiative check modifier in the group. That way, each player gets a turn each round and the GM also gets one turn. At the GM's option, however, they can make separate Initiative checks for different groups of opponents or even individual foes. For instance, the GM may make one Initiative check for an Imperial Officer and another check for his squad of Stormtroopers.
Joining a Battle
If characters enter a battle after it has begun, they make their Initiative check at that time and act whenever their turn comes up in the existing order.
In any battle that begins with a Surprise Round, you start the battle Flat-Footed. You remain Flat-Footed until your first regular turn in the Initiative Order. You can't apply your Dexterity bonus (If any) to your Reflex Defense while Flat-Footed.