Well, if you're talking about role-plays, basically what you do is write in the third person pov (though that's not necessary) and basically, you'll just be telling what goes on.
It might be better for you to go look at some rps currently going on and seeing what they're doing for you to get the idea.
It might be better for you to go look at some rps currently going on and seeing what they're doing for you to get the idea.