A faction is a group of units that are not necessarily of the same race. These are sets of units available to a particular leader and often reflect alliances between various races or divisions within a race. For example, Northerners cover orcs, trolls, and other races who often ally with the orcs in war. On the other hand, Loyalists only cover humans who are part of the army of the kingdom of Wesnoth or those who use a similar military system like the city-state of Elensefar. Other humans are parts of non-default factions such as outlaws.
Factions in multiplayer are determined by an era. Eras are groups of factions that cover a particular theme - for instance, the Default Era covers the common races that appear frequently during the history of Wesnoth, such as Undead. In eras, the units a particular faction can recruit are internally consistent with the version of the era. On the other hand, "factions" as they appear in single player campaigns can change according to the plot of the campaign. In the campaign Northern Rebirth, the player can only recruit peasants and woodsmen in the first scenario but gets more diverse recruit lists later on. The factions in single player usually do not match up completely with the factions in multiplayer.
The Battle for Wesnoth has a diverse amount of multiplayer factions. There are six factions that are currently in the Default Era, which comes with the game. Other factions are made by users and available as add-ons, usually packaged in eras with other factions. What follows is a list of the major factions, as sorted by era.
These are the factions present throughout the main portion of the game. They are available during multiplayer without requiring add-ons.
Main article: Drakes
The Drakes are a faction of dragon-like Drakes and their lizard Saurian allies. Drakes are descendants of dragons, but smaller in size. Saurians are fall smaller and from different ancestry. Together, the Drake faction has high mobility but low defense, leading to unusual tactics for a Default faction.
Main article: Knalgan Alliance
The Knalgan Alliance is a faction of Dwarves and their outlaw Human allies. Dwarves are an old race who live underground and have tough, but short, warriors. The outlaws are humans who are not socially acceptable among others of their race, but have become allies of the dwarves due to common enemies. This leads to a combination of tough and defensive dwarves who are only good on certain terrain and humans who can cover ground that dwarves are not good at fighting in.
Main article: Loyalists
The Loyalists are a faction of Humans who are loyal to the throne of Wesnoth. Humans are a versatile race who specialize in many different areas. Similarly, the Loyalist faction is a very versatile melee-oriented faction with important ranged support from bowmen and mages.
Main article: Northerners
The Northerners are a faction of Orcs and their allies who live in the north of the Great Continent, thus their name. Northerners consist of the warrior orcs race, the enslaved goblins, trolls who are tricked into combat by the orcs, and the serpentine naga. The Northerners play best by taking advantage of having many low-cost and high HP soldiers.
Main article: Rebels
The Rebels are a faction of Elves and their various forest-dwelling allies. They get their human name, Rebels, from the time of Heir to the Throne, when they started the rebellion against the evil Queen Asheviere. Elves are a magical race that are masters of the bow and are capable of living many years longer than humans. In harmony with nature, the elves find allies with the human mages, certain merfolk, and tree creatures called "Woses." Rebels are best played taking advantage of their high forest defense, mastery of ranged attacks, and the elves' neutral alignment.
Main article: Undead (faction)
The Undead are a faction of undead creatures and human practitioners of dark arts that usually accompany them. Often, these "Dark Adepts" are the units that do the most damage for the faction, but they have a major vulnerability - their practicing of this forbidden, evil magic has consumed all their energy and so they have no melee attack at all. The Undead are a very aggressive faction and the most powerful Default Era faction at nighttime.