Be they sandbox or themeparks, plenty of MMORPGs have hopped on the two-faction PvP bandwagon. A player rolls up on the red side or blue side at character creation, and that’s the side he’ll be fighting on for the rest of his character’s career — barring paid faction swaps, of course.
Inevitably, faction imbalances appear: sometimes the result of one side being aesthetically cooler than the other, sometimes a matter of numerical racial advantages, and sometimes generated by a steamrolling effect that prompts more and more people to pick (or switch to) the winning side, ensuring it wins even more.
MMORPGs and their offshoots have devised dozens of ways around this problem, ranging from bots, automatic buffs, and reward incentives to adding more factions (three-way RvR) and hoping they balance themselves, but in far too many games, the problem continues until the day the game closes up shop.
What would you do to solve the problem? Is two-faction PvP ideal for MMORPGs, or is there a better way for MMOs that want to avoid a total free-for-all?