Its the actual roleplaying aspect of Battletech and mainly used for non-mech types of adventures. If you know any of FASA's old battletech game then that is what it is based on. I played it a couple times and had fun with it, but its best either with a GM who knows the universe very well and how battletech works, or a GM with a group of players who is willing to try something brand new and different and learn it as you go.
A good beginning group of character types is to limit players to making Inners Sphere characters only, no Clan aspects at all. This will put them in a disadvantage right away when or if they ever come up against Clan attackers. Another good idea is to make a group completely of mech warriors, or none at all, because if only one or two are actually mech pilots and half of your adventures require them to be in their mechs fighting on a battlefield, the other characters will feel left out.
It is possible to run a game where they are all soldiers fighting ground wars and skirmishes but its just not the same as fighting in a battlemech.
I don't know if this helps, but good luck and if you do try and run it, it is a fun game.
