Skirmish

Looking for Skirmisher, a group of Kig-yar shock troops introduced in Halo: Reach?

Skirmish is a game mode in Halo Wars and Halo Wars 2. Skirmish serves as the Halo Wars equivalent of custom games, allowing players to alter game settings, activate Skulls and play against custom teams of human or AI players in any map or gamemode.

Halo Wars
Skirmish in Halo Wars has 10 possible maps and two gamemodes available for play. However, purchasing the Strategic Options and Historic Battle DLCs for the original Xbox 360 release, or playing the Halo Wars: Definitive Edition, increases this number to 14 possible maps and five possible gamemodes. Asterisks (*) denote content only available via DLC or Definitive Edition.

Maps
 * Beasley's Plateau (2v2)
 * Blood Gulch (1v1)
 * Chasms (1v1)
 * Crevice (2v2)
 * The Docks (2v2)
 * Exile (3v3)
 * Frozen Valley (3v3)
 * Fort Deen (3v3)
 * Pirth Outskirts (1v1)
 * Labyrinth (2v2)
 * Release (1v1)
 * Repository (2v2)
 * Terminal Moraine (2v2)
 * Tundra (1v1)
 * Barrens (1v1)*
 * Memorial Basin (2v2)*
 * Blood River (1v1)*
 * Glacial Ravine (3v3)*

Gametypes
 * Standard
 * Deathmatch
 * Keepaway*
 * Reinforcements*
 * Tug of War*

Skirmish allows the game to be played as 1v1, 2v2 or 3v3 matches, with any number of players or AI on either team. Due to the custom nature of the match, the AI leaders can be assigned manually. In addition, the match can be set on Easy, Normal, Heroic and Legendary difficulties, with an additional Automatic difficulty implemented that adjusts the game difficulty based on prior performance in previous games. Once the game has been launched, Halo Wars Skulls can be activated, for both positive and negative effect.

Halo Wars 2
Skirmish returns in Halo Wars 2 as custom games-only, with the "Standard" gametype renamed to Deathmatch. However, Halo Wars 2 skirmish mode allows for much greater match customisation than Halo Wars. Players can choose to activate or deactivate the Fog of War, increase or decrease how many Resources players start with among other options. All maps and modes in Halo Wars 2 Skirmish mode are available for all players (though a handful of Halo Wars 2 maps are exclusively available for other modes such as Blitz and Terminus Firefight), though some leaders are locked behind DLC. However, DLC leaders can be used by AI even if the player does not own the DLC.

Maps
 * Ashes
 * Badlands
 * Bedrock
 * Fissure
 * Frontier
 * Highway
 * Mirage
 * Rift
 * Sentry
 * Vault
 * Fort Jordan

Gametypes
 * Deathmatch
 * Domination
 * Strongholds