A character can try to do anything you can imagine, just so long as it fits the scene the GM describes. Depending on the situation, your character might want to:
* Listen at door
* Use a computer terminal
* Explore a location
* Converse with an alien
* Bargain with a merchant
* Intimidate a thug
* Talk to an ally
* Pilot a vehicle
* Search for a clue
* Bluff an official
* Repair an item
* Swing across a turbolift shaft
* Move
* Duck behind a bulkhead
* Attack an opponent
Characters accomplish thing by making skill checks, ability checks, or attack rolls. While the rules for making these rolls follow the core mechanic, each type of roll is used for a slightly different purpose.