Avalon no Kagi, alternatively known as The Key of Avalon is an arcade game developed by Hitmaker and published by Sega on the Triforce arcade board. It is the third card arcade game by Sega. It is a combination of sugoroku style board game and combat trading card game.

It was often compared to Culdcept, and is able to be played by multiple players at once, using a free in and free out method where other players can drop in and drop out of a match at any time. The cabinet reads a deck of up to 30 cards.

Sega Logistics Service announced it would end service on the machines on March 31, 2017.