The Unique Games Conjecture (UGC) is a conjecture made by Nevanlinna Prize winner Subhash Khot of NYU in 2002. It states that the Unique Games problem is NP-hard, and is one of the famous open problems in computational complexity theory. It especially has implications in hardness of approximation; for instance, it implies that the problem of approximating maximum cut for graphs by a better constant than given by the Goemans-Williamson algorithm is NP-hard.

At the 2019-2020 Tel Aviv Theory Fest, MIT professor Elchanan Mossel and NYU professor and Khot made a bet that a correct proof of UGC will be uploaded to arXiv by 2030. In early 2018, Khot, along with Dor Minzer and Muli Safra, made a significant advance toward proving UGC in a paper. Harvard professor Boaz Barak agreed to referee the bet.