The Rating Game is a competition whereby high-class devils compete using themselves and their servants either for prestige or to resolve disputes. The games are fought typically on special fields where any collateral damage to the surroundings are minized. Typically, the battle ends when the "King" or leader on one of the opposing sides is defeated.
There are cases where special rules are in place for particular rating games, such as the battle between Sitri and Agares, where a "Capture the Flag" rule was used as the objective.
It has been mentioned that the Rating Game is a relatively new phenomenon in the underworld, and as it has grown in popularity, those victorious in the game have gained much prestige and wealth. In particular, House Phoenix, whose members have the power of immortality are particularly suited to doing well in these games, and have fared incredibly well since the Rating Game has become popular.
Even if a servant subsequently becomes high ranked and possesses their own peerage (and thus becomes a "King" for their own rating games) they must continue to answer the call of their existing master. Thus, Issei, who is Rias Gremory's pawn, even if he is promoted or otherwise comes to have his own peerage, will always have to participate on Rias' behalf and be her pawn
142.205.241.253 17:11, March 27, 2012 (UTC)Wilhelmson