(1) Rocket Propelled Grenade. Used in combat situations.
(2) Role Playing Game (tabletop). Game in which the player takes on another personality to have fun.
(3) Role Playing Game (video game, turn based). A game that is frowned upon by fans of FPS
for it's strategical approach. More easily described as a "Playable Anime".
(4) Role Playing Game (video game, active battle). Fast paced, can appeal to even FPS
fans. I have personally proved this in 5 cases.