Total Annihilation: Battle Tactics is the second of two expansion packs for the popular RTS computer game Total Annihilation, released on June 30, 1998 in the United States. Its features include 100 new missions as either the Arm or the Core, four new units (the Arm Stunner & Phalanx and the Core Neutron & Copperhead) and new keyboard shortcuts. Six new multiplayer maps are included, and, for the first time in the Total Annihilation series, some single-player missions are set on acid and crystal worlds.