Each Legendary Duelist has an associated color of Gate Key. To Duel a Legendary Duelist at the Gate, the player must spend both a number of "plain" Gate Keys and a number of colored Gate Keys. However, it does not cost any Gate Keys to Duel a Legendary Duelist who appears in Duel World outside of the Gate.
During special events, event Duelists require event items instead of Gate Keys to be Dueled at the Gate.
There are different Gate Key costs depending on the Level the player chooses to challenge the Legendary Duelist at, with a higher cost for higher Levels.
|Level||"Plain" Gate Keys||Colored Gate Keys|
|10||24 Gate Keys||7 Colored Gate Keys|
|20||40 Gate Keys||14 Colored Gate Keys|
|30||64 Gate Keys||28 Colored Gate Keys|
|40||104 Gate Keys||56 Colored Gate Keys|
Each Legendary Duelist requires both plain Gate Keys and a specific color of colored Gate Keys to be challenged at the Gate.