Key Items are unique items essential for story progression or unlocking new areas. You cannot sell or discard them. Examples include the Pokédex (to record Pokémon data), Running Shoes (to move faster), Bicycle (Mach Bike for speed, Acro Bike for tricks), Devon Scope (to reveal invisible Kecleon), Go-Goggles (to cross the desert), Itemfinder (to locate hidden items), and the Eon Flute (to summon Latias/Latios after the Elite Four). Many key items are given to you by NPCs as rewards for completing tasks or progressing the story. Always check your Key Items pocket in the Bag to see what you have and what it does.
