Pokémon Red and Blue Version

Pokémon Red and Blue Versions, simply referred to as Pokémon Red and Blue, are the first two international Pokémon releases. In Japan, the original pair were Pocket Monsters Red and Green, which were then followed by enhanced versions, Pocket Monsters Blue. Pokémon Yellow, which was based upon the anime series, would later be released internationally.

Internationally, the games were referred as "Pokémon", as it is a romanized contraction of the Japanese brand, "Poketto Monsutā" (Pocket Monsters).

Gameplay
At the start of the game, Professor Oak brings the player (officially known as Red) to his lab to choose his starter Pokémon: Squirtle, the -type, Charmander, the -type, or Bulbasaur, the -type. After selecting his Pokémon, Red has frequent battles with other Pokémon Trainers and his own rival, officially referred to as Blue. Red also stops the criminal organization Team Rocket several times and defeats their boss, Giovanni.

Walkthrough
After you finish naming yourself and your rival, leave town through the north exit. Professor Oak will stop you and take you to his lab where you will be able to choose one of three Starter Pokémon; the Fire-type Charmander, the Grass-type Bulbasaur, or the Water-type Squirtle. Your rival, whom Oak has also called to his lab, will always choose the Pokémon with a type advantage over the one you picked and you two will engage in battle. After you are finished head north past Route 1, towards Viridian City.

Once at Viridian City, head straight to the PokeMart and pick up a parcel for Prof. Oak. Return to Pallet Town and deliver the parcel to Prof. Oak. Now walk back to Viridian City and walk east, to Route 22, where you will battle your rival. After that, head to Route 2 and then Viridian Forest. After making your way through the Forest, head north to Pewter City for your first gym battle.

Now that you are in Pewter City, go to the gym in northeast Pewter City. Brock is the gym leader here and he will use the rock/ground-type Pokémon Geodude (Lv 12) and Onix (Lv 14). Once you have defeated him, walk east to Route 3 and than to Mt. Moon.

After battling Team Rocket in Mt. Moon, you will reach Route 4 and then Cerulean City. Before battling the Gym, go North to Route 24. Defeat your rival and travel to the Sea Cottage where you will meet Bill. Help him out and he will give you a ticket to use later. Head back to Cerulean and go to the gym. There, you will battle Misty, who uses the water-type Pokémon Staryu (Lv 18) and Starmie (Lv 21). Now travel through the house right above the gym and battle the Team Rocket Grunt. Now head South to Route 5 and take the Underground Path to Vermillion City.

Now go south to board the SS Anne. Take the stairs directly to your left. Travel west until you run into your rival. Defeat him and enter the Captain's Room. Rub his back and he will give you the HM Cut. Now leave the SS Anne after training your Pokémon against the trainers and use Cut to enter the Gym. Search the trash cans until you find a switch. Than the next switch will be either next to, above, or below the trash can. Lt. Surge uses the Electric-type Pokémon Voltorb (Lv 21), Pikachu (Lv 18), and Raichu (Lv 24). Now head west to Diglett's Cave. Travel through until you reach Route 2. Head south until you meet on of Oak's assistants. If you have obtained enough Pokémon, he will give you the HM Flash. Go back to Vermillion. Go to the Pokémon Fan Club and talk to the President and he will give you a Bike Voucher. Return to Cerulean City.

Once at Cerulean go to the Bike Shop to receive your free bike. Now head west to Route 4 and enter the Rock Tunnel. Use Flash to see you way through the Rock Tunnel. After you find your way through the Rock Tunnel, you will reach Route 10, and then Lavender Town. Now go through Route 8 and go through the Underground Path to reach Route 7 and then Celadon City.

Once you enter the City, take the path directly above you and enter the large building to obtain an Eevee. Now head into the Game Corner. Battle the Rocket Grunt and enter their secret base. Battle all of the Grunts until you obtain the Lift Key. After that, take the elevator to level 4 where you will battle their boss, Giovanni. After you have done that, go into the Department Store and head up to the roof where you will need to buy a drink. You can share this drink with the guards in between many cities and routes so you can freely go through each of them. Now head to the Pokémon Gym in the Bottom left corner of the City. The leader Erika uses the Grass-type Pokémon Victreebell (Lv 29), Tangela (Lv 24), and Vileplume (Lv 29). Now return to Lavender Town.

Once you reach Lavender Town, go into the Pokémon Tower and battle your rival (Note: You can also do this when you first reach Lavender Town). Use the Silph Scope from Giovanni to see the ghosts in the Tower. Travel all the way through and rescue Mr. Fuji. At his home he will reward you with the Poké Flute. Now go back to Saffron City.

Go to the Silph Co. to battle Team Rocket once more. Battle the Grunts and collect items as you please. Go to Level 5 to get the Card Key that unlocks the gates. Now head to Level 3 and open up the first gate. Use the teleporter there to take you to your rival. Defeat him and receive Lapras from the worker. Take that teleporter to Giovanni to battle him once more. The president will reward you with a Master Ball when you defeat him. Exit the Silph Co. and head to the Pokémon Gym. The leader, Sabrina, uses the Psychic-type Pokémon Kadabra (Lv 38), Mr. Mime (Lv 37), Venomoth (Lv 38), and Alakazam (Lv 43). The gym next door is an unofficial Fighting-type Gym. Defeat the leader and can choose to obtain one of two Pokémon, Hitmonlee or Hitmonchan.

The next path is up to the player. Either take Cycling Road or Route 12 to reach Fuchsia City. Both routes require the use of the Poké Flute to awaken a Snorlax and open up a new path. Once you reach the city, head north to the Safari Zone. Once in there, be sure to obtain both HM Surf and the Golden Teeth. Once you have obtain them, head to a house in the bottom right corner of Fuchsia City and give the old man his Gold Teeth. He will reward you with the HM Strength. Now you can head to the Gym. The Leader, Koga, uses the Poison-type Pokémon Koffing (two of them at Lv 37), Muk (Lv 39), and Weezing (Lv 43). Now that you have the HM Surf, you can enter the optional dungeons Power Plant and Seafoam Islands to capture Zapdos and Articuno respectively.

Now that you have all but two of the Badges, head to Route 16 and obtain HM Fly (if you haven't already). Fly to Pallet Town and Surf South to Cinnabar Island. Enter the Pokémon Mansion and get the Secret Key deep inside to get into the Gym. Once you get there, the leader, Blaine, uses the Fire-type Pokémon Growlithe (Lv 42), Ponyta (Lv 40), Rapidash (Lv 42), and Arcanine (Lv 42). Now Fly to Viridian City.

Once you get there, head to the Pokémon Gym. The Leader, Giovanni, uses the Ground-type Pokémon Rhyhorn (Lv 45), Dugtrio (Lv 42), Nidoqueen (Lv 44), Nidoking (Lv 45), and Rhydon (Lv 50). Once you have defeated him head east and battle your Rival once more. Defeat him and head to Route 23. Show off all of your badges and enter Victory Road. The Legendary Pokémon Moltres is in this cave. Once you have gotten through this cave, enter the Indigo Plateau. Defeat all Elite 4 Members, Lorelei (Ice Pokémon), Bruno (Fighting Pokémon), Agatha (Ghost Pokémon), and Lance (Dragon Pokémon). Now you get to battle the Champion, your rival. Once you have beaten him, you have completed the game to become the Champion!

Now that you are Champion, fly to Cerulean City. Head to the top of Route 24 and Surf to the Unknown Dungeon. In this cave rests the strongest Pokémon in the Kanto Region, Mewtwo.

Significant Changes From Pocket Monsters Red/Green and Pocket Monsters Blue (Japanese) Editions

 * The sprites of various Pokémon are somewhat changed to fit the American audience, as well as their names being altered to fit to their characters.
 * The themes for Lavender Town and the Pokemon Tower are changed so that the high-frequency acoustics are lowered dramatically, so as to avoid migraines caused by ear stress in younger players.
 * Cerulean Cave is given a noticeably different layout, though the original layout is retained in the remakes.

Trivia

 * At the time of Red and Blue's release in the US, there was criticism regarding the in-game sprites of various Pokémon, mainly due to the fact that the Pokémon did not have the same appearance as they did in the anime series, despite the fact the anime had followed the games. With the release of Pokémon Yellow, the sprites, along with many other additional features, were changed to match that of the anime.
 * The first generation of Pokémon handheld games: Red, Blue, Green, Yellow, and the remakes, FireRed and LeafGreen, are the only games that do not feature a Legendary Pokémon, rather it features the final evolutionary forms of the starter Pokémon.
 * Pokémon Red had an incredible number of glitches compared to the following games, the most prominent being the appearance of the most infamous glitch Pokémon MissingNo., which does not appear in any other game.
 * It is impossible to fully complete the Pokedex without doing the Mew Glitch.