How do you encourage players to RP during combat? I'm interested in techniques that will get players to do more than just announce attack rolls and damage. Many of my players will do a little RP, and often describe their attacks and I encourage them to do so. I try to "lead by example" and always describe NPC attacks with a bit of flavor. However, there are a few players that just won't RP during combat at all.
Here's an example of a typical interaction with "Sam" during a combat encounter:
GM(Me): "...and the Goblin shrieks with rage after you deftly dodge his dogslicer attack at the last moment. Ok, Sam, you're up!
[Sam looks up from his laptop screen and rolls some dice.]
Sam: "23...16 points of damage."
GM: "OK...what are you doing?"
[Sam looks at the GM like he is stupid.]
Sam: "Attacking."
GM: "With what?"
[The look intensifies.]
Sam: "Longsword."
*************
You all get the point. No role-playing, no descriptions, just dice and damage. This player _is_ having fun. He keeps coming back and requests that I run more scenarios. The funny thing is that outside of combat, "Sam" is a pretty good role-player. I just can't find a way to get him, and a few others, to RP the combat.
Does anyone have advice that's worked for similar types of players?