- "These cadets are far from ready."
- ―Jedi General Shaak Ti, to Bric, on Domino Squad's initial progress[src]
Domino Squad was a military unit of clone trooper cadets stationed on the planetKamino during the Clone Wars. The members of the squad, at first, proved unable to effectively work together as a team, but they ultimately passed their tests on Kamino and became full members of the Grand Army of the Republic.
After graduation, they were stationed at Rishi Station on the Rishi moon, a strategic point on route to Kamino. The majority of Domino Squad died during a Separatistattack on the base. The survivors CT-1409 and CT-5555 were subsequently absorbed into the 501st Legion.
Members of Domino Squad were clones of the bounty hunter Jango Fett and born on Kamino. During the Clone Wars, the members of Domino Squad started their last practice tests in the Citadel Challenge under Master Chief Bric and bounty hunter El-Les. During their tests, the squad members were not able to work together as a team and resulted in their failure. During their final test, the squad failed when they left CT-00-2010and were chastised by the ARC trooper, Clone Commander Colt, for their actions. Despite the setback, El-Les was able to convince Jedi General Shaak Ti to let the squad retake the final test. CT-782 tried to go awol, but was convinced to stay by malformed clone 99. Despite's Bric's attempt to sabotage the test, the squad were able work together and win the Citadel Challenge. The squad graduated and shipped out to fight the Confederacy of Independent Systems Droid Army.
The members of the squad were assigned to the Rishi moon's outpost under the command of Sergeant O'Niner. Following a meteor shower, the listening post was taken over by a group of commando droids that had arrived to the surface in droch-class boarding ship believed to be meteorites. Several members of Domino squad were killed, but the remaining members were able to escape. The squad was unable to warn Clone Commander Cody and Clone CaptainRex about the commando droids by using a droid attack flare. The squad met up with the two officers and were able to retake the base from the commando droids. Unfortunately, the droids had hot-wired the all clear signal and GeneralGrievous dispatched reinforcements to secure the base. The squad and the two officers decided to destroy the base in order to warn the Republic about the planned attack on Kamino. The group used liquid tibanna as explosive to destroy the base. The officers and squad fought the droids before abandoning the base. Unfortunately for them the detonatorwould not link, and so Hevy chose to stay behind and sacrifice himself by detonating the gas to destroy the base to warn the Republic.
Echo and Fives, now the only remaining squad members, and Rex and Cody were picked up by the Republic after Grievous' fleet fell back. Echo and Fives were decorated by Jedi Generals Obi-Wan Kenobi and Anakin Skywalker. They joined the 501st.