Factions

The faction system in Grim Dawn allows the player to take advantage of the reputation (and infamy) gained with the various groups of Cairn. Completing quests, turning in bounties, and defeating members of opposing factions earns reputation with friendly factions, which gives access to perks such as merchant discounts, special equipment from quartermasters, and new side quests. Killing members of hostile factions earns infamy with these factions, which makes more enemies of that faction spawn, and later grants access to Nemesis enemies.

Factions
The base game features 12 factions, of which at the start of a game 7 are friendly and 5 are hostile. The Ashes of Malmouth and Forgotten Gods expansions each add three friendly and one hostile faction, bringing the number of factions to 20.

Some initially friendly factions may become hostile depending on player choice.

Allied factions

 * Faction_Black_Legion_Icon.png The Black Legion
 * Faction_Devil's_Crossing_Icon.png Devil's Crossing
 * Faction_Homestead_Icon.png Homestead
 * Faction_Kymon's_Chosen_Icon.png Kymon's Chosen
 * Faction_Death's_Vigil_Icon.png Order of Death's Vigil
 * Faction_Rovers_Icon.png Rovers
 * Faction_Outcast_Icon.png The Outcast
 * Faction_Coven_Icon.png Coven of Ugdenbog
 * Faction_Barrowholm_Icon.png Barrowholm
 * Faction_Malmouth_Icon.png Malmouth Resistance
 * Faction_Bysmiel_Icon.png Cult of Bysmiel
 * Faction_Dreeg_Icon.png Cult of Dreeg
 * Faction_Solael_Icon.png Cult of Solael

Hostile factions

 * Faction_Aetherials_Icon.png Aetherials
 * Faction_Beasts_Icon.png Beasts
 * Faction_Cthonians_Icon.png Chthonians
 * Faction_Cronley's_Gang_Icon.png Cronley's Gang
 * Faction_Undead_Icon.png Arkovian Undead
 * Faction_Aetherial Vanguard_Icon.png Aetherial Vanguard
 * Faction_Eldritch_Icon.png Eldritch Horrors

Faction reputation
Depending on whether a faction is friendly or hostile, the player can gain either positive or negative reputation with it. In some cases (such as when turning in some quests), gained reputation can be lost, but this cannot make a friendly faction hostile even if the reputation with that faction would go below 0 (it is set to 0 instead). The following actions result in reputation changes:
 * 1) Turning in quests and bounties.
 * 2) * The player gains positive reputation with the faction that benefits from the quest (usually, but not always, the one that gains the quest).
 * 3) * If this quest was aimed against a hostile faction, the player may gain infamy with that faction.
 * 4) * If this quest harmed another friendly faction, the player may lose reputation with that faction.
 * 5) Defeating enemies.
 * 6) * If the enemy was a member of a hostile faction, the player gains infamy with that faction.
 * 7) * If some friendly factions have this hostile faction listed as an enemy, the player gains reputation with these friendly faction. This can only work if the faction is "known" to the character, which typically requires them to complete a quest for that faction on any difficulty.
 * 8) * Reputation changes are affected by what kind of enemy is defeated. Heroes, bosses, and nemeses grant more reputation that regular enemies. Enemies of any kind with a level far below that of the player don't affect reputation at all.

There are two sets of reputation tiers that form the progressions for friendly and hostile factions. Reaching higher tiers with a faction grants perks that are listed below.

Friendly faction reputation tiers:
 * Tolerated (0 to 1,499)
 * Friendly (1,500 to 4,999)
 * Respected (5,000 to 9,999)
 * Honored (10,000 to 24,999)
 * Revered (25,000)

Hostile faction reputation tiers:
 * Hostile (1 to 1,499)
 * Despised (1,500 to 7,999)
 * Additional champions start spawning, sometimes with monsters that do not normally spawn in an area appearing to bolster their forces.
 * Hated (8,000 to 19,999)
 * Heroes of that faction start spawning more often wherever their forces are found. In the case of Kymon's Chosen and the Order of Death's Vigil, this will be the first time their heroes are encountered.
 * Nemesis (20,000)
 * Nemesis enemies of that faction start spawning in that faction's territory. Nemeses are rare and very powerful bosses, but they drop more loot than usual bosses and are more likely do drop rare blueprints.

Bounties
Factions offer bounties via their respective bounty tables. These are small quests where the player can earn additional rewards and reputation. There are a total of 145 bounty missions across the 7 friendly factions.

Faction equipment
Each friendly faction offers its own specific equipment for purchase, available from the faction quartermasters as rewards for gaining reputation.

Reputation items
Grim Dawn features items that amplify reputation gains with factions.

Writs
A writ is a consumable item that boosts a character's reputation gain with its respective faction by 50%. Unlike mandates, writs are soulbound, i. e. they cannot be transferred. Even though it's possible to purchase multiple writs from a single faction's quartermaster, only one writ per faction per character can actually be used.

Mandates
A mandate is a consumable item that boosts a character's reputation gain with its respective faction by 150%. Mandates can be transferred between different characters. Even though it's possible to purchase multiple mandates from a single faction's quartermaster, only one mandate per faction per character can actually be used.

Warrants
Nemesis bosses have a chance to drop warrants, which boost infamy gained with the respective faction by 50% across all difficulties. Warrants can be freely traded between players.

Faction choices
There are some considerations that apply whenever the game gives the option to become hostile with a previously-friendly faction. Such a choice locks out that faction's quests and bounties, their quartermaster, and makes writs and mandates for that faction unavailable. It also makes that faction available as an enemy, meaning the ability to earn items (including monster infrequents), experience, reputation, and to defeat their nemesis, which also gives access to warrants for that faction. As such, it may be useful to have separate characters to get the benefits of all choices (which is time-consuming), or at least to take different sides on different difficulty levels (which, hovewer, has its own downsides such as reputation resets). There also may be moral or roleplay points made for or against specific choices.

The subsections below describe the specifics of each individual choice in more detail and do not offer the generic advice listed above.

Kymon's Chosen vs Death's Vigil
Each faction has their faction vendor items to consider. TODO: describe.

TODO: Quest asymmetry...

The choice affects the events of the Forgotten Gods expansion slightly. TODO: describe.

With or against the Outcast
Siding with Anasteria will make it more difficult to earn reputation with the Black Legion. In addition, Anasteria provides a significant amount of information about the game's lore and backstory if left alive, and provides even more such knowledge in the Ashes of Malmouth expansion.

Siding with the Black Legion soldiers will give access to an additional dungeon and the ability to farm Anasteria for her unique drops.

With or against Barrowholm
Choosing the diplomatic solution with Barrowholm gives the ability to fight two bosses: the celestial boss Ravager and the easily-repeated boss Larria.

Choosing to attack Barrowholm gives access to an additional dungeon and the nemesis, Reaper of the Lost.

Witch cult choice
Unlike with the other choices, the factions not chosen do not become hostile, so there is no loss of items incurred. However, only the quests for the chosen faction are available, and while the main storyline quests have identical rewards, the Honored-tier side quests provide blueprints unique to both difficulty and faction. As such, it's required to use several characters to get all the rewards.

The Bysmiel cult may be the fastest one to play with: it's possible to get extra Blood of the Watchers for future difficulties, and its quests are less "out of the way" than the other factions. Its Honored-tier quest is also simpler than the other two.

Particular notes on each:
 * Cult of Bysmiel:
 * Main quest unique area: Veiled Den (Eldritch lands) with the boss Galfang, who has no unique drop.
 * Honored-tier quest: Kymon's Deserters, an easy "Find the NPCs" quest.
 * Korvan Swiftness, a leaping and fire movement augment.
 * Cult of Dreeg:
 * Main quest unique area: Edge of Reality (Chthonic) with the boss Ishtal, who does not have a unique drop.
 * Honored-tier quest: Future is Madness, to kill the boss Inarah (no unique drop).
 * Dreeg's Vector, a teleport and acid movement augment.
 * Cult of Solael:
 * Main quest unique area: Blood Wastes (Chthonic void) with the boss Onarix, who does not have a unique drop.
 * Honored-tier quest: Word of Rahn, finding and aligning statues in Korvan City.
 * Rahn's Might, a shield-based movement augment.