Advance Wars: Dual Strike stars two new characters: Jake, and Rachel (Jake's advisor). These are the primary protagonists of Dual Strike and members of the Orange Star Army, and are accompanied by several other new protagonists, including Sasha, Grimm, and Javier, members of the Blue Moon, Yellow Comet, and Green Earth Armies respectively.
The Black Hole Army has returned under a new commander, Von Bolt. He is accompanied by his Bolt Guard: Jugger, Koal, and Kindle, along with Hawke and Lash from the original Black Hole Army. Using a new technology called a Black Obelisk, Von Bolt is draining Omega Land of its energy to give him eternal life, and is also starting to use this power to produce a bio-weapon named Oozium 238, a strange slime-based monster that devours anything in its path. However, Hawke notices the energy draining (which also is turning Omega Land into a desert) and questions its use. After uncovering Von Bolt's plot, Hawke is betrayed and Von Bolt attempts to swarm Hawke and Lash with Oozium 238. After the Allied Nations’ COs save Hawke and Lash, the COs, along with Hawke and Lash, begin to turn the tide against the Black Hole Army. Both Hawke and Lash provide valuable intelligence of the Black Hole weaponry and its plans for Omega Land.
With this information, the Allied Nations slowly corner the Black Hole Army, leading to a battle in the middle of the Crimson Sea. After destroying the last Black Obelisk, the Allied Nations proceed to the final battle where they fight Von Bolt and a giant oozium known as the Grand Bolt. After destroying the Grand Bolt, Hawke (or Jake, based on the player's decision) destroys Von Bolt's life support chair, supposedly causing both Hawke and Von Bolt to die in the aftermath. With the Black Obelisks gone, Omega Land begins returning to normal. However, Hawke is revealed to have stolen Von Bolt's chair and escaped, leaving Von Bolt either dead or barely alive.
Gameplay in Dual Strike is relatively unchanged from the first two Advance Wars titles. The player takes the role as a CO of an army (more often than not, the Orange Star Army). The player moves the army across a 2D tactical map. If able, the player can then attack an enemy unit, capture a base, or other different actions. To win a battle, usually the player must either eliminate all of the enemy troops, or capture the enemy's base (certain maps have different objectives, however).
Troops vary in strength, movement, and attacking style. Infantry, for example, can capture bases, but are fairly weak, while Rocket Launchers can hit units from far away, but are defenseless in a head-to-head battle.
Terrain also effects the gameplay. While the main terrain is plains, there are also cities, forests, mountains, and other usual geographical features. Depending on terrain, the gameplay shifts slightly. Forests, for example, offer better defense, but are hard to navigate through.
COs (commanding officers) also have different tactics. COs offer different strengths and weaknesses. Colin, a Blue Moon CO, can buy units cheap, but at the cost of weak firepower. While Sonja, a Yellow Comet CO, can keep the number of units left in a group a secret, and has one more space of vision in fog of war.
New in Dual Strike are Tag-team battles. In certain battles, a player can pick two COs to lead one army, alternating at request. Once both power meters are filled, they can launch Tag Power. Here, the leading CO gets the added boost of a Super CO power. Once the first CO is done, instead of ending a turn, the player changes CO. Once this happens, units may move again, now with the benefits of the second CO. Depending on the CO, the player may get an extra boost. Pairings usually happen between either very close family of friends (Sonja and Kanbei, Colin and Sasha, etc.), or between COs of different tactics (Max and Grit, Eagle and Drake).