At the very start of Baldur's Gate 3 Act 3, you'll come across the circus that one of your companions (you can guess which one) is extremely excited to go in. If you do, you'll encounter a lot of different games that you can play and a lot of different side quests to mess around in, but one of these quests involves a Genie and a wheel.
How To Beat Akabi The Genie
The Genie is named Akabi, and he'll challenge you to spin his wheel to attempt to win. You'll lose if you try, every single time, and this is because he's wearing a ring that allows him to subtly use Mage Hand on the wheel to prevent you from beating him. If you sneak behind him and steal the ring before playing, however, then you'll win the wheel, and he'll be so furious with you that he'll send you to another plane of existence.
This plane of existence is infested by Dinosaurs and appears to be based on the Dungeons & Dragons plane of Chult. You'll have to either sneak or fight your way through the Jungle to get to a portal that you can use to leave, and as you reach the portal you'll likely notice a locked chest. If you lockpick this chest then you'll find a Legendary Weapon called Nyrulna, which is the true treasure of beating Akabi.
Nyrulna is a trident that deals 1D8 piercing damage in addition to dealing 1D6 Thunder damage and can be thrown at an enemy to create a 3D12 explosive area of six meters. It gives you an extra three meters of movement and jumping, immunity to fall damage, a glowing weapon, and cannot be forced out of your hand, making it one of the best weapons in all of Baldur's Gate 3.