What is a competition sponsored by a brand that requires skill or effort from participants?

A competition sponsored by a brand that requires skill or effort from participants is best defined as a contest. Contests typically involve participants showcasing their abilities, talents, or efforts to win a prize, which distinguishes them from other promotional activities like giveaways that do not require such effort or skill.

In contrast, a giveaway usually involves the random distribution of prizes without the need for participants to demonstrate any particular capability. A challenge could imply a broader context of competing against a difficult task, but it may not specifically align with the branding and promotional aspects often associated with a contest. Lastly, a campaign refers to a broader marketing strategy that incorporates various promotional activities, including contests, but does not solely denote the competition aspect. Therefore, a contest precisely captures the essence of a skill-based competition endorsed by a brand.