Count Dooku's war chest was a massive cache of valuable goods and artifacts stored in Castle Serenno on the planet Serenno. Throughout the Clone Wars, Count Dooku amassed this cache through worlds pillaged by the Confederacy of Independent Systems, as well as the inhabitants of Serenno itself. Between 19 BBY and 18 BBY, the Galactic Empire carried out an operation to ship the cache off-world, led by clone stormtrooper Captain Wilco. Though the operation was largely a success, the unexpected intervention of Clone Force 99—who were attempting to steal a small portion of the cache to maintain enough wealth to remain free from the Empire—resulted in approximately 15% of the cache being scattered across Serenno.
Dooku's war chest first appeared in the first episode of Star Wars: The Bad Batch's second season, "Spoils of War," which premiered on January 4, 2023. Head writer Jennifer Corbett wanted the episode to have a crossroads mission in which the Bad Batch could walk away or obtain the war chest to make their dreams come true. The writers decided to use Dooku's palace because they knew it had a lot of treasure.