"The World Ends with You" features "psych pins", decorative pins which possess powers that only Neku can activate while wearing them. Psych pins are used for combat, for "Tin Pin Slammer/Marble Slash", or as trade value for money or equipment. Most pins, particularly those used in combat, can become more powerful as the player accumulates "Pin Points" (PP) which can also lead to evolution of the pins into more potent versions. Pin Points are commonly earned through battle, but can also be earned through a period of inactivity with the game, by interacting with other DS players or randomly if none are found. Each of these methods influences the growth of pins within the game.