Interaction with Objects. A character’s interaction with objects in an environment is often simple to resolve in the game. The player tells the GM that his or her character is doing something and the GM describes what, if anything, happens. 

Timing. If an interaction with an object happens in a combat round or during some other fast-paced situation, then the timing and extent of the interaction is regulated by the rules on combat rounds.

Ability Check. Sometimes an interaction will require a successful ability check. For example, if the lever that the character decides to pull is rusted in position, the GM might call for a Strength check to see whether the character can wrench the lever into place. The GM sets the Difficulty Class (DC) for any such check based on the difficulty of the task.