The rules can be
found here, but the short version is this:
- All actors roll for initiative scores.*
- Turns take place in that order - a turn is when you can focus on an effort, and the game focuses on you.
- You can react to another character's action on another turn, but priority goes to the character taking her turn, then to the initiative scores.
- When the last turn ends, all remaining actions are lost, and everyone gets 3 more to spend in the next round.
It has some benefits
@hawkeyefan mentioned - like it's easier to use teamwork when you can coordinate actions, versus waiting for the turn-conveyor-belt.
*Just realized that step might be avoidable if it's tied to the PC's last roll...hmm....