In order to unlock trophies, you must own a game that supports the trophy feature. All new games support trophies and some older games have been patched to support trophies. Check out our Trophy List & Guides page to see which games support trophies.
In order to unlock a trophy, you must complete a task within the game. You can see what the requirements for unlocking a trophy are by checking the [Trophy Collection] menu under the [Game] menu on the XMB. For example, to earn a gold trophy in Super Stardust HD you must get a 10x Multiplier.