A term describing the total collection of plays that a team has practiced and could potentially run during a game. The offense, defense, and special teams will all have specific playbooks with the complete set of plays that can be called in each situation. A playbook is usually a physical binder given to players when they join a team. Players who are traded or released from a team are always asked to turn in their playbook before they leave to keep other teams from getting their hands on their plays.
The playbook is the traditional term for the collection of plays that a team can call during a game. Playbooks will have a variety of plays for both the offense and the defense, and in terms of both running and passing plays. There will be plays that are commonly used, and plays that are rarely used but pulled out in specific occasions. Using all the plays in the playbook is considered to be "emptying the playbook", and usually involved a lot of trick plays. Defensive plays will be more general, and tend to be more focused on assignments and formations than specific routes. A team's playbook is closely guarded to avoid having a team be able to plan for them.