Sheldon Licenses are a type of currency introduced in Splatoon 3 that can be used to acquire new weapons in Ammo Knights, which differs from previous games where players instead used Cash.
Sheldon Licenses can be obtained by increasing the player's level and by increasing a weapon's Freshness to level 1. Each weapon costs 1 Sheldon License to purchase. Unlike in previous games, weapons above the player's current level can still be bought, although they cost 3 Sheldon Licenses each instead of 1.
Gold Sheldon Licenses
In addition, there are also Gold Sheldon Licenses that can immediately unlock a weapon regardless of the player's level. Players who import their Splatoon 2 save data at the beginning of Splatoon 3 receive three Gold Sheldon Licenses after completing the first online battle, which is currently the only way to obtain them.
If the player has one, a Gold Sheldon License is spent automatically when purchasing a weapon above the player's level, or when purchasing any weapon with no regular Sheldon Licenses remaining.
Gold Sheldon Licenses do not have a counter in the user interface. Instead, Sheldon will tell the player how many they have left after they make a purchase in Ammo Knights.