Special Features. The Gem Of A Joker slot will be available with William Hill Vegas until September when it will launch with all Live 5-partnered mobile casinos. Studio's latest blockbuster slot features new jackpot bonus that awards Multipliers of between x5 and x2, the player's stake. . Online gambling is illegal in some. Grab 10 Free Spins to play a trio of fun-filled games, each day you stake € Choose from: Gem of a Joker Instapots™ · Starlite Fruits™. Studio's latest blockbuster slot features new jackpot bonus that awards Multipliers of between x5 and x2, the player's stake. Grab 10 Free Spins to play a trio of fun-filled games, each day you stake € Choose from: Gem of a Joker Instapots™ · Starlite Fruits™. Developer Live 5 has announced the launch of its new slot Gem Of A Joker InstaPots exclusively with William Hill Vegas.