"Player factions" refers to groups or teams of players in a game who join together to achieve common goals, compete against other factions, or form alliances within the game's virtual world. Full definition
When this takes place, the magical shields protecting each faction's base will lower, making them susceptible to enemy attacks from creatures — the Lost — and other player factions. (wccftech.com)
This will grant players faction bonuses like increased damage and health regeneration. (ibtimes.com)
The Elder Scrolls Online will have solo and group questing, public dungeons, guilds, and massive PvP warfare that sets the game's three player factions against one another for control over the region of Cyrodiil and the throne of Tamriel. (mmorpg.com)