Pokémon Blue Version is a single-player role-playing game with turn-based battles and monster-collecting mechanics. It is one of the paired titles that introduced the Pokémon series outside Japan, released alongside Pokémon Red Version.

The story follows a young Pokémon Trainer who sets out from Pallet Town with the goal of completing the Pokédex, an encyclopedia of all known Pokémon species. Guided by Professor Oak and rivaled by Oak’s grandson, the player travels across the Kanto region, capturing and training Pokémon, battling other Trainers, and defeating the eight Gym Leaders in order to challenge the Pokémon League. Along the way, the player confronts Team Rocket, a criminal group that exploits Pokémon for profit, and works to thwart their schemes.

Gameplay is presented from a top-down perspective and alternates between exploration and combat. Players capture Pokémon in the wild using Poké Balls and can carry a party of up to six creatures at a time. Battles are turn-based, with each Pokémon having a set of elemental types, hit points, and up to four moves that include damaging attacks and status effects. Fainted Pokémon must be revived at a Pokémon Center or with healing items. Victory in battle grants experience points, allowing Pokémon to level up, learn new moves, and in many cases evolve into more powerful forms.

Progression involves exploring towns, caves, and routes while solving simple environmental puzzles, such as navigating the Rock Tunnel or using abilities like Cut to remove obstacles. Players must earn Gym Badges in sequence, which allow the use of special hidden techniques outside of battle and open access to later areas. The ultimate goal is to assemble a strong team capable of defeating the Elite Four and becoming Champion of the Pokémon League.

Pokémon Blue Version includes 151 species, but not all are obtainable in a single game. Certain Pokémon are exclusive to Blue, requiring players to trade with Red owners through a link cable to complete the Pokédex. Battles and trades between players are central to the design, making multiplayer interaction a key component despite the primarily single-player structure.

Compared to the earlier Japanese release Pocket Monsters Midori (Green), Blue Version features revised graphics, audio, and code based on the Japanese Pocket Monsters Ao (Blue). These improvements include adjusted encounter rates, redesigned sprites, and modified dungeon layouts. The international releases consolidated these revisions into Pokémon Red and Blue as the definitive paired versions.