The shopkeeper is a non-playable character in Slayin. It allows the player to open the in-game shop.
The shopkeeper wears a brown cloak that covers the head and body. It carries a sack of lighter colour over its back. The face is a shade of green with red eyes and a mouth that juts out from the face. When the shopkeeper makes an appearance at the start of a level, a speech bubble with a brown exclamation mark appears over its head. The speech bubble disappears once the Knight, Wizard or Knave reaches the shopkeeper.
The shopkeeper makes an appearance at one end of the screen the farthest away from the player's character after five levels have been completed. The shopkeeper then presents the player with a display of items that can be purchased in exchange for coins. If the player waits too long, the shopkeeper will disappear from the screen and will only return after the player has completed five more levels.
With the arrow keys, any item selected will display that item's description as well as its price. The player can buy as many items available in the shop as they want, so long as they have enough coins. When an item is purchased, it becomes usable after exiting the shop. If the player lacks coins or red orbs necessary to buy an item, it will fade into the shop's background and the words "You can't afford that" will be displayed in place of the item's description.