The actor submitted his plea Thursday, a day before he was supposed to be arraigned. As for the conditions of his release -- the court ordered Baldwin not be allowed to drink, possess a gun or talk to potential witnesses UNLESS it's regarding the continuation of filming "Rust."

He will no longer need to appear at his hearing Friday.

As we reported, Baldwin's been charged with involuntary manslaughter in the death of Hutchins -- the District Attorney initially tacked on a firearm enhancement to the charge, but that was dropped earlier this week after Baldwin pointed out the version of the enhancement statute prosecutors cited wasn't effective until 7 months after the shooting.

It could have major implications for Baldwin -- the gun enhancement charge could've resulted in a mandatory 5-year prison sentence. Now that it's gone, he's only looking at up to 18 months behind bars if convicted ... and could end up with just probation.

The enhancement was also dropped against armorer Hannah Gutierrez-Reed.