Prerelease:Pokémon Red and Blue/Early Development
This is a sub-page of Prerelease:Pokémon Red and Blue.
The idea of Pokémon all started with the childhood of one man: Satoshi Tajiri. Born in 1965 in Machida, Tokyo, he spent his childhood roaming the then rural area, namely catching and collecting bugs, his favorite hobby. However, as the years went by, so did urbanization, forcing Tajiri to leave the dwindling insect population and find his next passion. Tajiri soon found himself sucked in the world of arcades and video games, this newfound obsession inciting him, due to the lack of media surrounding the topic, to create a fanzine which would share tips and tricks about certain games. This magazine, which he named Game Freak, slowly took off over time, which led to Tajiri meeting a young artist by the name of Ken Sugimori, who, unbeknownst to all, would also end up an essential aspect of what would later become Pokémon.
However, as Game Freak grew, so did Tajiri's frustration with the video games of the time, finding them generally unpolished. He then thought of creating his own game, which, as 1989 rolled around, finally started to take form as Nintendo released the Game Boy. Upon witnessing its technicalities, namely the connectivity brought about by the Link Cable, with Tajiri immediately thinking about living creatures traveling from one console to the other thanks to said cable. Soon after, Tajiri and Sugimori turned their self-published fanzine business into the eponymous video game company.
Originally geared toward puzzle games, the success of Square's Makai Toushi SaGa cemented Tajiri and his passion project of an RPG. Tajiri took his childhood love for critter collecting, as well as kaiju and superhero TV shows, and pitched the project he dreamed of for so long: Capsule Monster.
Capsule Monster Pitch
Capsule Monster was indeed the original name of the project, with the "Capumon" stored in "capsules" similar to ones found in gashapon machines, and clearly inspired by Ultraman's "Capsule Kaiju". However, the great similarity in both name and concept to the latter caused Game Freak to ultimately run into troubles when it came to copyrighting the project, prompting a renaming to "Pocket Monster", or "Pokémon" for short.
Pitched along the project was an illustrated booklet, also known as Capsule Monster, which provided numerous sketches, concept art, and even a concept pitch! This fabled folder was partially shown in the TV show Game Center CX, and later in a 2019 edition of Famitsu, and though dated to 1990 on both the cover and the Kanto layout map, this document is comprised of elements from visibly different stages of development. The contents of the booklet will be described below:
Caption: Game Freak Inc. 1990 – Producer: Satoshi Tajiri
The cover illustration, which depicts a trainer sending out a lindwurm-like creature to battle a stubby reptilian creature. These were likely one-off designs meant to showcase the look of a battle. This scene is also either an early look at, or an inspiration for the games' intro cutscene, which in the final release shows a Nidorino fighting a Gengar.
Project name CAPSULE MONSTERS Details Nintendo Game Boy ROM package Size 2M Bit ROM battery backup 64 K SRAM ●Aim A game that makes the most out of the characteristics of the Game Boy, and one that is interesting because it is a Game Boy game. We want to make the most out of that concept. ① One of the characteristics and features of the Game Boy is its Link cable. We use said Link Cable as the key to creating new ways to play while using it. We will purse new game mechanics that are unique to the system, rather than following the concept of the Famicom. ② Moreover, we propose new opportunities for children to communicate with each other beyond the LCD screen and to the world at large. Think of this as a proposal for communication in a broader sense, in the real world, not only in terms of game design, but also in terms of oral communication, interaction with friends, and game relationships. ③ We tried to reexamine the meaning of "money" in this hypothetical game world. We hope this will be a small hint for children to broaden their thinking from the exchange value to the value of "money" and "things" in the real world.
The aim of the project in its basic technical basis.
A (Hypothetical) Story Set in the Not-So-Distant Future... It’s been a month since the release of Capsule Monsters, a monster game that incorporates RPG elements into a dungeon-covered overworld. You know those vending machines that sit in front of candy stores and toy shops selling capsule toys called "gashapon", right? I guess I could describe the game as being similar to the excitement you get from collecting those capsules. In Capsule Monsters, 200 types of virtual monsters live in equally virtual underground dungeons on the Game Boy. The game's hero can befriend these monsters and win them over to his side by increasing his Charisma, a game parameter not yet widely known among Japanese audiences. Charisma is featured in the Wizardry series, but it seems like Japanese games have yet to make use of it. Naturally, Capsule Monsters also allows you to capture creatures alive rather than defeating them in battle, as you've done in RPGs up till now. The roster of over 200 types of monsters includes creatures that you won't necessarily encounter, creatures who will choose not to ally with you, and creatures who you’ll miss the chance to encounter entirely, and thus never be able to catch. My friends and I call these "mirage monsters". It just so happens that I have three Green Dragons, which only appear very rarely in the corner of an underground dungeon, four levels down. In order to catch just one of these mirage monsters, players of a certain level have to spend an average of two hours wandering around a particular area. My friend, Takuji, doesn't have any Green Dragons, but he is allied with two Fireflies instead. In class, discussion about Capsule Monsters really heats up after the bell rings. Who has which illusory characters? How many? We're not just bragging, exactly. Once my friends and I come to an agreement, we connect our Game Boys via Link Cable and then we can use it to trade monsters. That's why we get excited, because we’re negotiating which monsters to trade for what, and how many. Takuji and I finally finished negotiating. He'd agreed to trade one of his Fireflies for two of my Green Dragons. But I still felt like our exchange was a little unbalanced. I asked if he wouldn't mind adding five Powerkings, monsters with the strength you might expect to see in soldiers, and we finally struck a bargain. Powerkings have a high encounter rate, and you'll quickly run into them if you wander around dungeons. They're strong, though, and the theory is that, if you have a lot of them, you can put them to work as soldiers when you run into other monsters. Takuji and I hooked up the Link Cable and traded monsters. The Game Boy plays sound effects as the monster data is being transferred, so we could hear the monsters' cries. Word of mouth has turned Capsule Monsters into a hit. While I was riding the train to school, I discovered that students from other schools played too. I pulled my Link Cable out of my school bag as I addressed them. "Excuse me." I said. "I have a Firefly and a Green Dragon. What do you guys have? How about a trade?"
The concept pitch, which was meant to give off the cultural impact the game was aiming for. While things mostly line up, some peculiar differences can be noted. Namely, underground dungeon exploration seems to have been one of the game's main selling points, which eventually evolved into the idea of exploring the region to complete the Pokédex. The idea for the "Charisma" stat was scrapped entirely, and so was the concept of "creatures who will choose not to ally with you". Meanwhile, the idea of monsters "which only appear very rarely in a [dungeon corner]" was thankfully never implemented (with the only outlier being Generations III and IV's elusive way of catching Feebas). The number of Pokémon was also cut down to 150, and it appears that the player was able to trade multiple Pokémon at once, something completely impossible in the final releases.
"Mirage Monsters" and "PowerKings" are also terms which are entirely missing from the final releases, with them simply corresponding to the idea of absurdly rare monsters and "powerhouses" respectively. The placeholder critters "Firefly" and "Green Dragon" are also mentioned, and while the former are rather culturally-relevant insects in Japan, the latter are a common trope, with colored dragons being popular in JRPGs. Namely, here we have a direct reference to the Chromatic Dragons from Final Fantasy III, which are boss-like monsters that can only be found as rare encounters in a specific floor of the final dungeon; one such dragon even happens to be green. Funnily enough, while these "Pokémon" were likely never intended to be more than simple names, Generation III would later introduce fireflies (Volbeat and Illumise) and two green dragons (Flygon and Rayquaza).
Link Cable Functions
Proposal of a new way of playing using the Link Cable "CAPSULE MONSTERS" proposes a new way of playing using the Gameboy's Link cable. 1 – Using a Link cable, you can trade Capsule Kaijus and items with your friends, or even sell and buy them. In general, there are many games for the Game Boy that share a world using the link cable. The proposal on how to use the cable in this game is slightly different from the traditional type; it's literally a "transfer". Imagine a standalone monster that crosses the borders of its habitat and moves to another ecosystem. "CAPSULE MONSTERS" will share and exchange time and experiences. 2 – As an option or as a second objective, there is also a "battleground" mode; a match mode using the cable. You can fight monsters your friends have in this fighting place. 3 – However, it is not the only thing that makes this game appealing. You will be engaged in collecting numbered Capsule Monsters and items. If you're missing a monster, you can exchange it with your friends, and it will surely be fun. Most children have a drive to collect things. Remember when you were a child in the old days, collecting Menko cards, bottle caps, baseball cards, chocolate stickers, Bikkuriman stickers, carddass, and so on? Actively collecting small items has always been a popular game among children.
Information regarding the different ways the Link Cable could be used. Mostly lines up, and while items can't be traded by themselves in the final games, Generation II would later allow you to trade a Pokémon holding an item. Moreover, while item collection never ended up becoming a defined aspect in the final releases, Pokémon: Let's Go, Pikachu! and Let's Go, Eevee! would later introduce little "nothing items" such as bottle caps, springs, nice rocks, shiny things, and the likes of it, all in order to convey the idea of a child picking up cool things found on the ground while on adventures.
A really old sketch of what Kanto could look like, included below the paragraph describing the Link Cable functions. While appearing to be completely different, flipping the map upside-down reveals that it is indeed based on the Kantō region. In terms of locations, a cemetery, lake, desert, military base, and the Tokyo Tower can be seen, all places which never appear in the final games. The cemetery was repurposed into the Pokémon Tower, and the city of Tokyo into Saffron City, albeit without any tower. The desert, meanwhile, was likely based on the Tottori dunes, was planned to make a comeback in the games' follow-up, though it sadly once again got scrapped. The sailboat was also likely reworked into the S.S. Anne, a luxury cruise liner that travels between different towns in Kanto.
A simplified map of the real-life region of Kantō, the basis for the eponymous region in which the final games take place. Likely used as a reference to show the resemblance between the two, as seen by it being included close to the early Kanto map.
Early Kanto Map
Dated 1990 is this early layout for the region, atop of which sits an early game logo. While extremely close to the final map, a few interesting differences can still be noted:
- Routes were split up, going from the 13 denoted here to the 25 seen in the final games.
- Route 23 (12-2 here) is much longer, which actually matches up with its in-game equivalent. The final Town Map shows this route as being shorter than it actually is so that the name banner could be added.
- Route 17 (9 here) actually turns around and enters Fuchsia City from the north rather than the west. The Safari Zone is found north of the city in the final games, which may have caused the aforementioned re-routing. The progression of Cycling Road's real-world counterpart, the Tokyo Bay Aqua-Line, may also have been a factor, as construction only began in mid-1989.
- Saffron City is referred to as "T", possibly a reference to "Tokyo", this city's basis.
- An extra area is listed south of Celadon City. Known only as "C", it does not have any roads connecting it to other places. It appears to have been intended to be a rather large city, likely a seaside one given its positioning. This area was most definitely scrapped very early on, as its early in-game equivalent feels rather quickly slapped together.
Sketches showing the player roaming the overworld, as well as exploring an underground dungeon. The former has a very old-school RPG vibe, with a player exploring a shrunken-down overworld map. Three item balls can also be seen in the dungeon, perhaps a Voltorb or two in disguise, which would make sense as it is based on Mimic-enemies and was among the first batch of Pokémon created.
Various mockups used to explain certain gameplay mechanics. Here, a "Beast Tamer" (likely a precursor to the Tamer class, known in Japanese as "Wild Animal Tamer") with six "capsules" sends out "No. 23 Godzillante". Interestingly, the menu when facing the Tamer has the option "Talk" (はなす) instead of the "POKéMON" one. The fight itself is then shown, depicting two creatures with strong likenesses to Godzilla and King Kong, even being known as Godzillante and Gorillaimo. These are but mere placeholder designs created solely to showcase the early battle mechanic, which is evidenced by their kaiju basis. Interestingly enough, Gorillaimo's hat could be a reference to Ninten, the main character of Ape Inc.'s Mother. The battle screen itself is rather rudimentary, with the Pokémon being seen from the side rather than being front and back, the PPs (here known as TPs, likely standing for "Technical Points", similar to TMs) being shown, and the total damage of the used move being stated (Gorillaimo receiving 300 damage after Gozillante "breathes fire" on it).
Below is a simple screen displaying the start of a "trade", the text translating to "No. 23 Godzillante sold to Ichirou for 2000G". This is interesting, as it reveals that one could sell their Pokémon as opposed to simply trading them. Gold, a staple in RPGs, is also listed here as a currency, the final games instead using yen. The trade animation, in itself, appears similar to final, though there the Poké Ball leaves from the top of the screen rather than the side of it.
Found last is a mock-up for the stats screen, starring "Dragon4" (ドラゴン4), a by-the-number cartoony dragon creature. Essentially everything is different here:
- PPs are again referred to as TP.
- The movepool section consists of a single attack, here a move called "Fire Breath" that requires 70 TP. This, alongside the battle mock-ups, may indicate that Pokémon were at first intended to only learn one move.
- The ID number, OT name, and status/type bar are missing.
- The word "Level" is written in English instead of Japanese.
- The four stats listed are "Attack – Speed – Intelligence – Defense" instead of "Attack – Defense – Speed – Special". It's unknown what "Intelligence" would have consisted of, though the stats here indicate that this dragon was definitely more brawn than brain.
- This creature is also listed with a "Value of 128000 Gold", indicating that each species had a certain price attributed to them.
First Sprite Sheet
Included after the storyboards are a series of three early spritesheets. For comparison sake, the first two will be split into individual sprites, with the full sheets available here. The first sheet contains the first Pokémon which were created, going all the way up to Nidoqueen, which sits at index number 16.
|The front horn is smaller and lacks its drill motif, while the striped pattern on its stomach extends further up. Has lighter shading on its lower belly. Notably, it is also listed as sitting at index number 0, while in the final games this spot is occupied by a null value and isn't actual data.
|An earlier version of Gyaōn (ギャオーン), a scrapped kaiju Pokémon which can be seen in the Satoshi Tajiri manga's popularity poll. This design features a much more simplistic pose and design, and it's likely this sprite dates back to the time when this Pokémon was still known as "Gyarth" (ギャース, or "Gyaasu"). Its index number would eventually be used by Rhydon in the final game.
|The shading on its head is darker while its stomach is much lighter.
|Has a larger sprite overall, smooth ears instead of spiky ones, and looks up rather than down. The inside of its ears also has a line running through it, similar to what can be seen with Nidoran♀.
|The original design for Clefairy before it was reworked into a cuter Pokémon. Looks more reptilian, with some plating, claws, and lacking any sort of curls. Has the same pose as in the final games. Is potentially seen in the piece of concept art depicting how Pokémon help with daily life, which, if correct, reveal that it also had spikes on its back.
|Likely an early design of Spearow, as seen by their matching index number. The general shape of the beak is the most similar part to the final version's sprite, but some elements such as the head feathers were later used by Pidgeotto and Pidgeot instead. It also appears to have claws at the end of its wings, something which was scrapped completely.
|Bigger sprite, with less shading on its upper half and a different facial expression.
|Has a completely different sprite, though the Pokémon's design in and of itself is identical.
|Has a confused expression instead of a smile, very similar to Slowpoke's sprite. Its right arm is not raised, it has different tail shading, and its "Shellder" has a different lower jaw and facial expression.
|While its name isn't shown, its index number corresponds to Ivysaur in the released game. The lower half of this sprite matches with Ivysaur's, while the stem and flower match with Venusaur's.
|Has slightly different toes, different facial expressions, the overall shading is lighter.
|Its arms are not raised, it doesn't appear to have thumbs or a pattern on its legs and stomach, its tail is thinner, its tongue is more forked, and its feet smaller.
|Has a bigger sprite, larger eyes, and different shading.
|Has a bigger sprite. Its mouth is closed and its expression is more mellow. It also lacks defined hands, and the shading is different throughout its entire body.
|Has much shorter ears and a much smaller grin, appears to lack defined hands, and has a more visible tail.
|Has a bigger sprite, smooth ears instead of spiky ones, a different eye, no visible nose, and no whiskers.
|Has a more visible claws on its right hand, and different shading on its chest and face.
Second Sprite Sheet
The second early spritesheet, this one going all the way up to Tangela, which sits at index number 30. On the topic of index numbers, all Pokémon from this sheet are listed with extra numbers beside their index ones, which correspond to their base cry ID.
|Cubone. Has a raised left arm, a white belly, and different shading on its skull.
|Rhyhorn. Looks far smoother, and was probably not intended to be covered by a rocky armor at this point. Also has different toes and a different facial expression. Is seen in the piece of concept art depicting how Pokémon help with daily life, there carrying barrels around.
|Has a bigger sprite. Lacks its curly ears, and has a more defined right flipper and muzzle. Is seen in the piece of concept art depicting it being used to travel across the sea.
|Arcanine. Is known as "Wing" instead of "Windie" (ウインディ). Has a less hirsute fur coat, hooves instead of paws, a different posture and facial expression, and lacks its iconic stripes. Is evidently already based on a Kirin, though here on the more horse-like depictions of them.
|A scrapped Pokémon evidently based on Mecha-Godzilla. Name is likely a pun on "Ohm", a unit of electrical resistance whose symbol is Ω (capital Omega). This index spot was overwritten by Mew in the final games. May have later inspired Aggron, a metallic Kaiju-inspired Pokémon introduced in Ruby and Sapphire.
|The original design for Gyarados before it was reworked into a sea-serpent inspired Pokémon. It has a vastly different design, depicting it as an eyeless leech/lamprey/tardigrade/sandworm. It does however have a similar base concept, being a fierce serpentine monster with a gaping maw. Bears some striking resemblance to the Sandworm from Final Fantasy III, which released in April 1990.
|Has a sprite whose design is clearly more akin to its evolution, Cloyster. Much like Ivysaur once being a Venusaur-like Pokémon, Shellder was once Cloyster, though lacking its main horn and large spikes.
|Tentacool. Is known as "Ambler" instead of "Menokurage" (メノクラゲ), its early name potentially coming from the word "Umbrella", in reference to its shape. Much like Ivysaur and Shellder before it, it shares some traits which were reworked for its later conceived evolution, the extra tentacles and the squid beak going to Tentacruel (though the beak ironically enough ended up elongated into a crooked bird-like beak). Its head is also smoother than what can be seen in the final sprite.
|Gastly. Has a different facial expression, with it lacking the impish look of the final sprite.
|Scyther. Basically went from a dragon with insect-like features to an insect with dragon-like features.
|Staryu. Is known as "Mimī" instead of "Hitodeman" (ヒトデマン), with this early name visible in the piece of concept art where it can be seen battling Blastoise. Sprite is identical to the final, aside from some extra pixels here and here dotting its lighter parts.
|Blastoise. Is known as "Karabajio" instead of "Kamex" (カメックス), with this early name visible in the piece of concept art where it can be seen battling Staryu. Interestingly, this early name appears to be a reference to the Italian painter Carvaggio, which could make it a reference to the Teenage Mutant Ninja Turtles franchise, whose titular turtles are also named after Italian painters. This would also be a nice nod to the word "Carapace", in reference to Blastoise's turtle basis. Sprite is identical to final, aside from some slight differently-shaped toes.
|Pinsir. Identical to final.
|Tangela. Appears to have denser vines, slightly more refined feet, and a more mischievous expression.
Overworld Sprite Sheet
Caption: Character Sprite Sheet
What has to be the earliest spritesheet when it comes to overworld sprites, predating even the one from the asset leak. When compared to the latter, a few differences can be noted:
- Sprites are organized as having the walking animation beside the static one. Meanwhile, the two sheets included in the leak have the walking sprites separate in the lower rows.
- The Player's sprites are even more primitive, namely having a poorly stylized cap. Interestingly, the final games use a variant of this sprite when the player rides his bicycle.
- The sprites of the player riding his bike are missing.
- The heavyweight man NPC has a dark gray shirt with a neckline, as opposed to a bland solid black one.
- The Player's mother doesn't have walking sprites yet, nor do the chubby man and pigtails girl NPCs.
- The "Monster" sprite and the "mysterious character" are presented as full sprites, instead of having both halves stored atop each other.
- Most shockingly of all, present in the lowest row is a female version of the Player character, one who even bears resemblance to the female trainer seen in early concept art! Being able to choose between a male and female playable character would only become a series staple starting with Pokémon Crystal.
The capsule is opened and closed by a button on the back. Twist the capsule to lock it. Monster Capsule™ - Portable Monster Capsule PCM-55R - $198.00
A small Rhydon seen emerging out of a precursor to the Poké Ball, with its button being found on its bottom rather than on its side, and its red and white parts being swapped. This latter aspect is interesting, as it reveals that Voltorb was initially conceived as an upside-down Ball. This sketch also showcases the idea of Pokémon shrinking down to fit inside their Ball, a concept which remains in the final games but is only rarely discussed (most notably in Pokémon Legends Arceus). This aspect is also prominent in the Pocket Monsters Special manga.
A stylized depiction of a two Pokémon battles. The first is captioned "Yadon VS. Ghos", which is interesting as "Yadon" is the Japanese name of Slowpoke, Slowbro being known as "Yadoran", suggesting that a renaming happened at one point in development.
The second fight, meanwhile, is captioned "Karabajio VS. Mimī", the early names of Blastoise and Staryu, the two Pokémon seen fighting. While these Pokémon's designs appear slightly different than in the final releases, with Staryu lacking its gold enameling and Blastoise missing its signature water cannons and having more defined ears, it's likely they are simply off-model. Indeed, one of the sprite sheets included in the pitch folder contains virtually identical sprites for these two Pokémon, suggesting it was just a simple design inconsistency.
Two pieces of concept art depicting how trading is done, with a local trading device being shown, as well as an area, known as "PMC TR", which features two much larger machines. Funnily enough, the smaller one features not only a doodle of Arcanine, but more shockingly has very visible Sony branding on it. Moreover, while the larger public trading center never found its way into the final releases, Pokémon Crystal does feature a very similar area known as the "PokéCom Center", which during development even featured two large similarly-shaped machines to what is seen here!
Concept art of how life was envisioned with Pokémon, with a trainer using his Rhyhorn to carry drums around, another taking what is likely Clefairy's original design for a walk, and another letting his nondescript Rhydon-like Pokémon drink from a nearby fountain. This all fits in with what Sugimori described in an interview, with Pokémon having clear definite roles.
Caption: Hotel Check-In
A trainer checking into a hotel, a staple of classic RPGs. The final games would scrap the idea in favor of Pokémon Centers, which merely heals your team and does not offer any room for the trainer to rest in. While the final game does feature a hotel in Celadon City, it is purely decorative and only features a barebones half-empty lobby.
This second illustration links with the hotel concept, showing a female trainer healing her Pokémon in her hotel room, with the machine interestingly only featuring four slots, the final games allowing a maximum of six Pokémon to be part of your team.
Caption: "Wanna trade for this guy?" "For a Nidoran? Don’t be ridiculous!"
The aforementioned female trainer, this time walking about, only to be stopped by a fellow trainer looking for a trade.
Caption: "Hey, Mister, I’ll take this one, please." "Lapras... I dunno if you’re tough enough to handle it yet, kid..."
A male trainer attempting to purchase a Lapras in what appears to be an early version of the Poké Mart. Interestingly, the shopkeeper resembles the sumo enemies from Game Freak's debut title Quinty. In comparison, Poké Marts in the final are held by shopkeepers with large glasses, and the shops only provide items. The "Pokémon" seen here in the background are once again simple placeholder designs, and not scrapped designs.
The idea of buying Pokémon was eventually made less prominent as Pokémon became less like pets and more like friends, though in Generation I you can still "buy" some in exchange for tokens at the Celadon City Game Corner's prize exchange booth (indeed, this is the only way to obtain Porygon in Gen I). The route to Mt. Moon also contains a con man who tries to convince you to buy a Magikarp from him.
Caption: Heading for the harbor atop Lapras...
The male trainer from before riding on a Lapras, whose design matches the early sprite seen in the pitch folder. Interestingly, while the final game opts for a non-descript fish-like silhouette for the Pokémon the player surfs on, Gold and Silver always display a Lapras.
Caption: Cave exploration
The male trainer again, this time exploring a cave with his Rhydon, encountering a small reptilian hatchling which can be seen taking its first steps away from its nest. Once again a simple one-off design meant to showcase the idea of exploring remote areas, discovering new Pokémon in the process. The concept of Pokémon laying and hatching from eggs would later find its way into Gold and Silver, where it became a series staple.
Caption: Grave of the Mythical Beasts
This second illustration links with the exploration concept, showing the player at the foot of a tower, multi-level dungeons being a staple of RPGs. The caption refers to this place as a tomb, revealing it to be a precursor of Lavender Town's Pokémon Tower. This is likely where Gastly and Gengar were intended to reside.
Alongside the aforementioned concept document, developer interviews later revealed some more insight as to what went into perfecting the soon-to-be Pokémon formula:
It first started with designs of dinosaurs and monsters in a super-deformed style. They had fangs and long tails, and spikes jutting out all over their bodies. It started with Pokémon like Rhydon and Nidoking, for example. And when we looked at them all together, the designs felt rather uniform [...] as the games' development progressed we added the idea of "types" to the game system.
Interviewer: There are many different types of Pokémon, like Water and Grass. Did you have that in mind from the beginning? Sugimori: The idea came to us during development. Battles would get monotonous if there were only strong and weak Pokémon, so by affixing types to the Pokémon we were able to give the fighting more depth. There were also characters that were born of their types. Interviewer: That means that the characters you came up with in early development were created without much regard to type, then. Sugimori: That's right. At first, Pokémon were more dinosaur-like than the ones you see today. Beginning the story by choosing one of three Pokémon of different types was also something that came about in the middle of development. It’s pretty common at our company to have a game change completely during the development period.
The idea of typing turns out to have been a later addition, with Pikachu being an example of a Pokémon born out of the need for a Pokémon of a certain type, here an electric one.
Interviewer: Why did you decide to have 151 Pokémon? Sugimori: At first, the game was more RPG-like. It was only in the middle of development that the goal of the game became completing your Pokédex. That's when memory capacity and deciding on a good number of characters became an issue. We actually wanted to have more. We designed around 1.5 times more characters we actually used. Interviewer: Why did the game change from an RPG to one where your goal was to complete your Pokédex? Sugimori: When we were writing the text for the Pokédex, we started talking about how fun it was to collect Pokémon. We hadn’t wanted to do a fantasy RPG from the start. We felt a story about a boy traveling to fill up his Pokédex was more appropriate for modern times than a tale of a hero battling an evil villain.
As seen in the concept pitch, early plans called for a total roster size of around 200 Pokémon, which can be seen in the final games' internal index list, which has a total of 190 entries. This is further confirmed in later interviews, which revealed that said scrapped Pokémon did have designs created for them and their potential incorporation into future releases is still on the table. This can be seen with some of the scrapped Pokémon, such as Kotora or the cut pre-evolutions, making a return in early builds of Pokémon Gold and Silver.
Interviewer: In a normal RPG, the protagonist levels up, right? But in the Pokémon games, your Pokémon mature as they travel with you. Why is that? Sugimori: At one time, the protagonist would fight as well. But then we asked ourselves "If you can fight on your own, what’s the point of having Pokémon?" Masuda: At first, the protagonist and his Pokémon had a human-pet relationship. When we started making the game, however, we wondered whether it wouldn’t be better if they were more like friends. That's when the story changed to one where everyone grew up together. [...] We designed it so that you'd feel your Pokémon were something that belonged to you, friends to you.
As hinted in the pitch, it appears that catching Pokémon worked similarly to recruiting party members in standard RPGs, with the player being an active fighter. This can also be seen in the fact that trainers in both concept art and the final games can be seen wielding whips, the protagonist even doing so early on In development.
Interviewer: Did you have everything planned out from the very beginning, right down to the little details? Or did you gradually add things along the way? Masuda: Game Freak's modus operandi is that we add ideas and break things down. For example, at one point we took out the health gauge during battles and tried using phrases like "That hurt", and "That really hurt", instead. That didn’t turn out to be very interesting, though, and we went back to using the meters. Rather than using an idea as-is, we all come together and ask ourselves whether there isn’t an even better idea.
Mentions of a short-lived different sort of battle flavor text, the final games using a simple mention of the Pokémon using its move, though a similar idea to the early one is that of "This move was super effective!" Further changes to the actual battle system, meanwhile, were discussed in the book Pokémon Taught Me The Meaning of Life. There, it is revealed that originally, the game was programmed so that even when already defeated, trainer battles would still trigger when walking by one. The wild Pokémon encounter rate was also significantly higher originally. The Trainer rebattling was omitted from the final release and the wild Pokémon encounter rate was significantly reduced.