Sam Jones -- Merciful Judge Gives Acting Pass

Sam Jones has been on his best behavior since he was let out of prison in 2012, so much so that a judge cut his probation short so he could go work on a new movie ... TMZ has learned.

As TMZ first reported, Jones was released from federal prison after serving 10 months following a guilty plea to conspiracy to sell more than 10,000 Oxycodone pills.

Jones was offered a role in the movie version of his show "Blue Mountain State." Problem was ... the movie was shot in Montreal, and Jones couldn't enter Canada while on probation.

He wrote to the court, "I really need this freedom to practice my craft again. It's been a rough road, coming back. But I'm almost there ... I need to work on this 'Blue Mountain State' movie. I need to work as an actor again."

The judge was merciful and ended Jones' probation early ... complimenting the actor for helping young people and the homeless.