Microsoft a detaliat DLC-ul pentru Halo Wars, acesta va adauga noi moduri de multiplayer cat si noi achievement-uri.Modurile de Multiplayer vor fi "Keep away Mode" (echipele vor trebuii captureze santinele pentru a castiga puncte inainte echipei adversare,echipa care va captura prima 3 santinele va castiga), "Tug of War Mode" (esentialul este sa distrugi cat mai mult dar combinatiile de arme vor aduce succesul) si "Reinforcement Mode" (fiecare jucator va trebuii sa isi adapteze tactica pentru a invinge).
"One and Done" (30 ): Score the winning point in a game of Keepaway against Legendary A.I.'s
"Pull Hard, Pull Deep" (20 ): Win and never trail in a Tug of War game
"Freak on a Streak" (20 ): Gain at least 15 population from a single wave in a Reinforcement game
"Living Loving Bug" (30 ): Obtain a Scarab during a Reinforcement game