Combat takes place in logical order, rather than leaving the order up to a chance roll. When characters first enter combat, the GM describes the scene to them, and allows the characters to decide amongst themselves what order to go in and what they plan on doing. Once the characters have decided how they will enter combat, the action begins with the GM logically deciding the order in which the combatants should go.
The exception to this is if the characters are surprised or initially attacked by invisible enemies, or some similar situations. The GM must be creative in making sure everything is done in a way that is both realistic and fair.
Optionally, some players may be too used to Initiative to stray from it. For this, roll and add the total (1-100) to the character's Reflexes. This is the order they can go in, with any ties rerolling against each other.
Combatants using guns or other ranged weaponry do not follow these rules.