Clone cadets taking part in the Citadel Challenge
The Citadel Challenge is defined as a specific training exercise. This exercise took place inside the training facility located in the military complex of Tipoca City, which itself was situated on the planet called Kamino.
The Citadel Challenge can be described as a capture-the-flag style drill. Cadets needed to navigate past sentry towers and typical infantry droids, ascend the incline, and secure the pole. Doing so would deactivate all of the droids and laser cannons. Various forms of protection were available, including walls and containers. The laser cannons were configured to only deliver a stun effect.
The Citadel Challenge was frequently implemented as a means of assessing whether cadet squads, for example Domino Squad and Bravo Squad, possessed the readiness for deployment into actual combat. When Domino Squad participated in this challenge, their initial performance was marked by disorganization and failure. However, after they learned the value of teamwork, the clones were successful in completing the challenge and ultimately graduated.
Until his passing during the Battle of Kamino, the physically atypical maintenance clone known as 99 held the position of janitor for the room where the challenge was conducted.