Sub-bosses are secondary antagonists in video games, often serving as challenging opponents that players must defeat before facing the main boss. They typically possess unique abilities and strategies, making them distinct from regular enemies. Sub-bosses can help to build tension and excitement in the game's narrative, providing players with a sense of progression. These characters often appear at key points in the game, acting as gatekeepers to more significant challenges. Defeating a sub-boss usually rewards players with valuable items or experience points, enhancing their skills and preparing them for the ultimate confrontation with the main boss, such as final bosses or main antagonists.