Accusations are flying around a California courtroom as two of the world's biggest electronics companies resume their long-running patent battle.
Making its opening statement Tuesday, Apple said Samsung copied the iPhone to figure out how to react and compete with it.
Apple is seeking to ban sales of several Samsung phones, including the Galaxy S3.
Apple's lawyers say the company deserves about 2 billion U.S. dollars for the infringement, but Samsung's lawyers fired back saying Apple was merely seeking to make up for losing its lead in the smartphone market.
The core of Apple's argument is that it revolutionized consumer electronics with the iPhone in 2007, risking nearly everything in the process. while Samsung took the easy way to success, copying many of its features and making billions of dollars as a result.
The trial is expected to last until early May.