Legality Changes by Yellow and Japanese Blue
Introduction
Every Pokémon generation introduces changes to legality halfway through, be it through events, updates to software, third versions, or something else. The first generation is no exception to this, featuring many minor changes across its second wave of releases. While Pokémon Red and Green were the first games released in Japan, Blue was later released through a CoroCoro magazine mail order promotion in 1997. It later got re-released for retail alongside Pokémon Yellow, arguably making them sequel titles.
This guide will go over changes that made a significant difference to the Pokémon themselves, such as access to better DVs or movepool changes.
Table of Contents
Japanese Blue Version
The Japanese version of Pokémon Blue is actually quite different to the Pokémon Blue that we got in the West; the version we got had legality based on Pokémon Green while still using a translated script from Japanese Blue, plus the updated sprites. This is why the "Raichu evolved" error got left in Cinnabar Lab, which led to various playground myths back in the '90s that turned out to be partly right with the revelation of Gorochu's removal during the original game's development. It's also the reason MissingNo. gets a glitched Pokédex entry in the international versions of Red and Blue, as it wasn't translated and thus calls invalid characters. Overall, our Blue version was effectively a mishmash of Green and Japanese Blue.
So what was in this Japanese Blue version, then? Let's go over that first.
Japanese Blue introduced the usual changes you would expect from a Pokémon version of this era: different wild encounter tables, Game Corner prizes, Celadon Mart items, and in-game trades. Because of this, though, the game introduces some otherwise unobtainable Pokémon and thus legality that is Japan-exclusive.
In-Game Trades
The main change Japanese Blue brings is its in-game trades, which are eligible for perfect DVs by virtue of not being tied to encounter rates. Because Tauros is a regular encounter in the other games, Japanese Blue is the only game capable of providing a perfect one. It also uniquely provides Pokémon evolving by trade, like Graveler and Haunter.
| Location | Pokémon to Trade | Pokémon Received | Nickname (Japanese) |
|---|---|---|---|
| Route 2 | Jigglypuff | Mr. Mime | まさる (Masaru) |
| Underground Path (Route 5) | Rattata | Poliwag | ロモたん (Romo-tan) |
| Route 11 | Rhydon | Kangaskhan | ロダン (Rodan) |
| Route 18 | Persian | Tauros | ぎゅうた (Gyuuta) |
| Cerulean City | Machoke | Haunter ~ Gengar* | ゴーすけ (Goosuke) |
| Vermillion City | Pidgey | Farfetch'd | アッカ (Akka) |
| Cinnabar Lab | Kadabra | Graveler ~ Golem* | さぶろう (Saburou) |
| Cinnabar Lab | Seel | Slowpoke | オスカル (Osukaru) |
| Cinnabar Lab | Growlithe | Krabby | どうらく (Douraku) |
| Unused Trade** | Butterfree | Beedrill | チクチク (Chikuchiku) |
*The evolution of these Pokémon cannot be cancelled. Both Pokédex entries are filled.
**This trade can be obtained through glitches, though it is obviously illegitimate.
These trades also have an effect on the minimum levels you can obtain some Pokémon at. This makes three Pokémon eligible for the official Pika Cup format through some fairly complex in-game trading. In fact, because of another localization error in Pokémon Stadium, each of these Pokémon can be seen in Round 2 despite being unobtainable internationally, which can be fairly confusing for those unaware. Golem and Kangaskhan are notably quite powerful in the format, changing the metagame a good bit.
- An eligible Golem can be obtained through trading a level 16 Kadabra at Cinnabar Lab.
- This means its minimum level is 16, which makes the Golem in Stadium's Round 2 completely illegal!
- An eligible Kangaskhan can be obtained by using Surf on Route 6 to catch a level 15 Golduck (5% encounter) and trading it with Yellow. Once in Yellow, trade for the Rhydon at Cinnabar Lab. After that, trade this Rhydon back to Japanese Blue and trade for the Kangaskhan at Route 11. This nets you a level 15 Kangaskhan.
- An eligible Muk can be obtained by doing the Kangaskhan method above and subsequently trading it for the Muk in Pokémon Yellow's Cinnabar Lab.
Wild Encounters
As is tradition with each version, various wild encounters were changed, including some changes that are quite interesting. Because Lickitung and Jynx are no longer obtainable via trades in Japanese Blue, they're instead distributed to the Safari Zone and Seafoam Islands, respectively.
| Pokémon | Location | Level Range | Encounter Percentage |
|---|---|---|---|
| Ditto | Rock Tunnel B1F | Level 18 | 10% |
| Lickitung | Safari Zone East | Level 25 | 4% |
| Lickitung | Safari Zone West | Level 28 | 1% |
| Jynx | Seafoam Islands B2F | Level 37 | 1% |
| Jynx | Seafoam Islands B4F | Level 39 | 4% |
| Rapidash | Cerulean Cave 1F | Level 49 | 10% |
| Raticate | Cerulean Cave B1F | Level 52 | 10% |
| Clefairy | Cerulean Cave B2F | Level 64 | 10% |
Because of these changes, Japanese Blue makes it possible to nickname Jynx at all. Japanese Blue was also the first time this applied to Lickitung before it was later put in Yellow's Cerulean Cave. Because both Lickitung and Jynx are wild encounters, however, it is impossible for them to get perfect DVs, and they're restricted to spreads that either reduce their Speed or reduce their Special. Without Japanese Blue, it's also impossible for a wild Lickitung to learn Wrap, Supersonic, or Stomp due to being obtained at quite a high level, causing it to learn Defense Curl over it.
Yellow Version
Pokémon Yellow brought far more significant changes overall, adding entirely new moves to Pokémon's learnsets alongside the usual changes each version of RBY experiences. Its encounter tables also naturally brought forth entire new changes to DV legality, though listing everything is nigh-impossible.
This table goes over the moves added to each Pokémon's learnset:
| Pokémon | Added Move(s) | Method |
|---|---|---|
| Charizard | Fly | HM02 |
| Butterfree | Gust | L28 |
| Flash | HM05 | |
| Fearow | Pay Day | Pokémon Stamp Event (August 1998) |
| Pikachu | Tail Whip | L6 |
| Slam | L20 | |
| Light Screen | L50 | |
| Fly | CoroCoro Magazine Event (c.1997) | |
| Surf | CoroCoro Magazine Event (c.1997), Pokémon Stadium Move Tutor | |
| Raichu | Tail Whip | Evolve Pikachu |
| Slam | ||
| Light Screen | ||
| Fly | ||
| Surf | ||
| Venonat | Supersonic | L11 |
| Confusion | L19 | |
| Flash | HM05 | |
| Venomoth | Supersonic | L1, Evolve Venonat |
| Confusion | L1, Evolve Venonat | |
| Flash | HM05 | |
| Diglett | Cut | HM01 |
| Dugtrio | Cut | HM01 |
| Psyduck | Amnesia | Pokémon Stadium |
| Golduck | Amnesia | Evolve an Amnesia Psyduck |
| Mankey | Low Kick | L9 |
| Screech | L45 | |
| Primeape | Low Kick | L1, L9, Evolve Mankey |
| Screech | L45 | |
| Kadabra | Kinesis | L1 |
| Alakazam | Kinesis | L1, Evolve Kadabra |
| Rapidash | Pay Day | Pokémon Stamp Event (August 1998) |
| Cubone | Tail Whip | L13 |
| Headbutt | L18 | |
| Marowak | Tail Whip | L1, L13 |
| Headbutt | L18 | |
| Chansey | Tail Whip | L1 |
| Tangela | Vine Whip | L29 |
| Scyther | Wing Attack | L50 |
| Pinsir | Bind | L21 |
| Magikarp | Dragon Rage | Tamamushi University Event (July 1998) |
| Eevee | Growl | L16 |
| Focus Energy | L36 | |
| Vaporeon | Growl | Evolve Eevee |
| Focus Energy | Evolve Eevee | |
| Aurora Beam | L36 | |
| Jolteon | Growl | Evolve Eevee |
| Focus Energy | Evolve Eevee | |
| Flareon | Growl | Evolve Eevee |
| Focus Energy | Evolve Eevee | |
| Smog | L42 |
The most notable change Yellow brought to the game was actually having a Pokémon that learns Kinesis. Prior to Yellow's release, Kadabra couldn't learn Kinesis, causing the move to become unused outside of glitches or Metronome. Once Yellow was released, Kadabra became able to use Kinesis at L1, meaning that wild Kadabra come with the move. However, this also means that Kinesis Kadabra from Yellow cannot have perfect DVs; to get perfect DVs, it must be obtained as a Game Corner prize as an Abra.
Pinsir was blessed with the move Bind, allowing it to be less of a momentum sink. Bind can act as a pseudo-U-turn in RBY, preventing Pokémon from moving as the user switches. It also allows Pinsir to chip Pokémon into Swords Dance + Hyper Beam range, which makes it a terror against paralyzed teams. Without this move, Pinsir is often forced out by Gengar and Haunter while letting them get off Hypnosis, as it only learns Normal- and Fighting-type moves and only has Seismic Toss to actually damage them. With Bind, it's possible to pivot out into an outright counter.
While only relevant in Stadium, Jolteon got bestowed with Focus Energy, a move that quarters the user's critical hit rate in RBY. In Stadium, however, it raises it by about 66%, giving Jolteon a savage critical hit rate of 71%. This makes it into a deadly sweeper in formats using Stadium mechanics, such as Stadium OU or Poké Cup. However, it also comes at the opportunity cost of moves like Rest or Pin Missile, as the combination of Thunder Wave + Thunderbolt + Double Kick is almost undroppable.
Charizard also learns Fly, which not only gives it a Flying-type STAB move, but also a decent way to exploit the semi-invulnerability glitch; if it experiences paralysis or confusion while flying, it'll get stuck in the air until it uses Fly again. Because it learns Swords Dance, an invulnerable Charizard is very capable of gimmicking its way to victory in niche formats that allow the semi-invulnerability moves, such as the in-game Yellow's version of Poké Cup.
While an insignificant change in the grand scheme of things, Yellow version was the first time Scyther actually got a STAB move: prior to this, Scyther only learned Normal-type attacks. Ergo, it was literally incapable of winning against Gengar, as Struggle is Normal-type in RBY. While Wing Attack does little to prevent such a humiliating defeat, it at least allows Scyther to deal damage to it.
However, as the following table implies, Pokémon Yellow doesn't just add moves to a Pokémon's movepool, it also shifts the levels around accordingly. This is mainly to balance in-game playthroughs more effectively. Because of this, there is some minor significance when applying version differences to level-limited formats, such as the Stadium Cups. In fact, it's arguably optimal to use Pokémon Yellow if you aim to play through these without glitches.
| Pokémon | Move(s) | Pokémon Red | Pokémon Yellow | Notes and Remarks |
|---|---|---|---|---|
| Butterfree | Confusion | L12 | L10 | |
| PoisonPowder | L15 | L13 | ||
| Stun Spore | L16 | L14 | ||
| Sleep Powder | L17 | L15 | Yellow is the only way to get an L15 Butterfree with Sleep Powder for Pika Cup. | |
| Supersonic | L21 | L18 | Yellow legalized Supersonic Butterfree for Pika Cup. | |
| Whirlwind | L26 | L23 | ||
| Psybeam | L32 | L34 | ||
| Pikachu | Thunder Wave | L9 | L8 | |
| Quick Attack | L16 | L11 | Yellow is the only way to get an L15 Pikachu or Raichu with Quick Attack for Pika Cup. | |
| Thunderbolt | Not learned | L26 | Pikachu is the only Pokémon in Generation I to learn Thunderbolt via level-up. | |
| Thunder | L43 | L41 | ||
| Swift | L26 | Removed | Pikachu has to learn Swift via TM in Yellow instead. | |
| Nidoran-F | Poison Sting | L14 | L17 | Trading a Nidoran-F back from Yellow can get Double Kick and Poison Sting onto a L15 Nidoran-F. This can be used to get an L16 Double Kick + Poison Sting Nidoqueen. |
| Tail Whip | L21 | L23 | ||
| Bite | L29 | L30 | You can technically use RGB to save a level to use Bite in Petit Cup, but it's outclassed by better options. | |
| Fury Swipes | L36 | L38 | ||
| Double Kick | L43 | L12 | Yellow legalized Double Kick Nidoran-F for Pika Cup. | |
| Nidorina | Poison Sting | L14 | L19 | |
| Tail Whip | L23 | L27 | ||
| Bite | L32 | L36 | ||
| Fury Swipes | L41 | L46 | ||
| Double Kick | L50 | L12 | ||
| Nidoqueen | Double Kick | From Nidoran-F or Nidorina | L12 | Only relevant for Trainers. |
| Poison Sting | L14 | Removed | ||
| Nidoran-M | Poison Sting | L14 | L17 | Trading a Nidoran-M back from Yellow can get Double Kick and Poison Sting onto an L15 Nidoran-M. This can be used to get an L16 Double Kick + Poison Sting Nidoking. |
| Focus Energy | L21 | L23 | ||
| Fury Attack | L29 | L30 | RGB can be used to learn Fury Attack a level earlier. Considering Focus Energy, this can be a gimmick set in Stadium, but Body Slam is normally better for consistent damage. | |
| Horn Drill | L36 | L38 | ||
| Double Kick | L43 | L12 | ||
| Nidorino | Poison Sting | L14 | L19 | |
| Focus Energy | L23 | L27 | ||
| Fury Attack | L32 | L36 | ||
| Horn Drill | L41 | L46 | ||
| Double Kick | L50 | L12 | ||
| Nidoking | Double Kick | From Nidoran-M or Nidorino | L12 | Only relevant for Trainers overall. Interestingly, in both versions, only Nidoking learns Thrash at L23. This creates learnset incompatibilities with Focus Energy and Fury Attack. It also creates an incompatibility with Double Kick in Yellow-banned formats. |
| Poison Sting | L14 | Removed | ||
| Venonat | PoisonPowder | L24 ~ L22 | ||
| Venomoth | Leech Life | L1 | Removed | |
| Poison Powder | L1 or L24 | L22 | ||
| Primeape | Rage | N/A ~ L28 | Primeape already got Rage via TM20, making this a largely irrelevant change. | |
| Kadabra | Confusion | L1 or L16 | L16 | Entries removed to make room for Kinesis. |
| Disable | L1 or L20 | L20 | ||
| Alakazam | Confusion | L1 or L16 | L16 | |
| Disable | L1 or L20 | L20 | ||
| Tangela | Bind | L1 | L24 | Moves were shifted around to make room for Vine Whip. |
| Absorb | L29 | L27 | ||
| Growth | L49 | L48 | ||
| Gyarados | Tackle | From Magikarp | L1 | Rebalanced for the fact that it's now catchable. This could also be considered a Trainer nerf. However, the Pika Cup rental Gyarados actually uses the removed attacks at L15, making it an illegal rental. |
| Bite | L1 | Removed | ||
| Dragon Rage | L1 | Removed | ||
| Leer | L1 | Removed | ||
| Hydro Pump | L1 | Removed | ||
| Eevee | Sand-Attack | L1 | L8 | |
| Quick Attack | L27 | L23 | Yellow can be used to get Quick Attack Eevee prior to L25 for Petit Cup, which is actually really important for its moveset. | |
| Tail Whip | L31 | L1 | This legalizes Tail Whip for use in Petit Cup. | |
| Bite | L37 | L30 | This legalizes Bite Eevee for use in Petit Cup on L30 builds, but Body Slam is normally more effective. | |
| Take Down | L45 | L42 | ||
| Vaporeon | Sand-Attack | L1 | L8 | |
| Quick Attack | L27 | L23 | ||
| Water Gun | L31 | L16 | Given Water Gun is a TM, this doesn't change anything, unlike Tail Whip and Bite. | |
| Tail Whip | L37 | L1 | This legalizes Tail Whip Vaporeon for use in Nintendo Cup '98 if Yellow moves are allowed. | |
| Bite | L40 | L30 | This legalizes Bite Vaporeon for use in Nintendo Cup '98 if Yellow moves are allowed. | |
| Acid Armor | L42 | L47 | ||
| Haze | L44 | L42 | Because a Pokémon can only learn one move via level-up at a time, Haze is prioritized over Mist. The only way to learn Mist in Yellow is by leveling up Vaporeon in the Pokémon Day Care near Cerulean City. | |
| Mist | L48 | L42 | ||
| Hydro Pump | L54 | L52 | Hydro Pump can be used two levels early in Poké Cup. | |
| Jolteon | Sand-Attack | L1 | L8 | |
| Quick Attack | L27 | L23 | ||
| Thundershock | L31 | L16 | This legalizes Thundershock Jolteon for use in Nintendo Cup '98 if Yellow moves are allowed. | |
| Tail Whip | L37 | L1 | This legalizes Tail Whip Jolteon for use in Nintendo Cup '98 if Yellow moves are allowed. | |
| Thunder Wave | L40 | L42 | ||
| Double Kick | L42 | L40 | ||
| Pin Missile | L44 | L47 | ||
| Agility | L48 | L36 | ||
| Thunder | L54 | L52 | ||
| Flareon | Sand-Attack | L1 | L8 | |
| Quick Attack | L27 | L23 | ||
| Ember | L31 | L16 | This legalizes Ember Flareon for use in Nintendo Cup '98 if Yellow moves are allowed. | |
| Tail Whip | L37 | L1 | This legalizes Tail Whip Flareon for use in Nintendo Cup '98 if Yellow moves are allowed. | |
| Bite | L40 | L30 | This legalizes Bite Flareon for use in Nintendo Cup '98 if Yellow moves are allowed. | |
| Leer | L42 | L47 | ||
| Fire Spin | L44 | L36 | ||
| Flamethrower | L52 | L54 | Flamethrower can be used two levels early in Poké Cup. | |
| Rage | Not learned | L28 | Rage was already learned via TM20, so it doesn't really matter. |
The Nidoran lines famously got Double Kick at level 12 via Yellow version, which is partly what made the early-game bearable when facing down Brock. This also gives them some minor extra coverage in Pika Cup, although you're probably better off using stronger moves like Earthquake, Thunderbolt, and Blizzard. It's technically possible to use Pokémon Red to learn Poison Sting prior to the threshold of level 15, though it's a largely useless move.
Most Eeveelutions got some love here; Eevee gets access to Quick Attack prior to level 25, making it a bit more viable for a Petit Cup playthrough in Stadium considering its awful base movepool. Vaporeon and Flareon also got access to their strongest moves at level 52—Hydro Pump and Flamethrower, respectively—making them slightly easier to fit on balanced-level teams in Poké Cup.
Events
Stadium Gift Pokémon
The first Japanese Stadium title—often colloquially referred to as "Stadium Zero"—allows Pikachu to be taught Surf if one clears the level 30 cup based on Nintendo Cup '98. In the second Stadium title, which was released internationally, if one clears Prime Cup Master Ball Round 2 with a Pikachu in their party without saving, so long as it is picked in the final battle, Pikachu can also be taught Surf. This is the most accessible method of obtaining a Pikachu with Surf, which is crucial to its success competitively, as well as accessing the Pikachu's Beach minigame in Pokémon Yellow.
Additionally, if one gets all 151 Pokémon in the Hall of Fame in Pokémon Stadium, they can receive a level 15 Amnesia Psyduck, which single-handedly turns its evolution from a thoroughly mediocre Pokémon into a significant threat, giving it a much-needed identity as a special sweeper. In fact, Amnesia Golduck is so strong, it was banned from RBY NU in 2020!
Japan-exclusive Event Pokémon
In Japan, a select few Pokémon were distributed that had otherwise unobtainable moves. While generally unimpressive, these would pave the way for more famous event distributions, such as the notorious New York Pokémon Center events in GSC. Because the RBY events were only available in Japan, these Pokémon cannot be used in international games, as trading them across regions causes save data corruption. These events are considered to be among the rarest of all time, normally being distributed to a pool of 20 players each. Due to the nature of these events, they are also Japan-exclusive legality, akin to Japanese Blue's DVs.
Pikachu first got Surf via event on June 12th, 1997 via the "Pokémon 2 Idea Contest" in Shogakukan's CoroCoro magazine. For this event, readers submitted Pokémon ideas for the then-upcoming Pokémon Gold and Silver titles. Tsunekazu Ishihara and Satoshi Tajiri selected their top 20 contestants, who sent in their cartridges to receive the Pikachu. Therefore, this Pikachu is extremely rare. This distribution would be repeated twice as a kind of raffle in later issues, each with 20 winners. However, two similar distributions were also performed for a Fly Pikachu, which is unobtainable in the West. Both Pikachu were distributed at level 5, though a Surf Pikachu can theoretically be obtained at level 3 through Stadium's Move Tutor.
Shogakukan also distributed a special Dragon Rage Magikarp at level 15 via the "Tamamushi University Hyper-Test" event in July 1998, wherein players submitted a series of answers to six tests in the CoroCoro magazine issues. The top 1,000 "students" of these Pokémon exams were entered into a raffle to be among 20 "professors" to obtain the legendary Magikarp. The rest (jncluding the raffle winners) obtained a special medal and promotional Pokémon card, both of which are considered to be extremely rare collector's items today, commanding gigantic prices online.
The final round of events with unique moves were the Pokémon Fan Club Chairman's Fearow and Rapidash, which were distributed with Pay Day in the August 1998 issue of CoroCoro magazine. They were at levels 25 and 40, respectively, and were otherwise normal Pokémon. This distribution was part of a greater "Pokémon Stamp" campaign where readers could obtain various collectible stamps, which featured the Red and Blue art sets on them. These weren't "real" postage stamps, though, just collectible ones. These stamps would continue being produced well into the 2000s and beyond, featuring later generation art sets.
Mew
Mew needs no introduction, being one of the most widely distributed Pokémon of its era and having a very heavy influence on RBY Ubers with its Swords Dance sets. It was most commonly distributed with a 5/10/1/12/5 DV spread, although exceptions exist, and the 2016 Virtual Console versions of the game had real-life events where players could get a Mew with 15 DVs in every stat. Most of the time, Mew was distributed at level 5. Mew was given out in many, many events worldwide, often in tournaments and other large gatherings. There have been some "groups" that have been identified, such as the YOSHIDA Mew, Nintendo character OTs, and more, giving each Mew a degree of intrigue.