Red, Blue & Yellow — Competitive Reference
Generation 1 is the original. 15 types only — no Steel, no Dark, no Fairy. Special is a single stat. Critical hits scale with Speed. RBY OU has been continuously played at top level for nearly 30 years and remains the franchise's longest-living competitive format.
Released
1996 / 1998
Region
Kanto
Engine
Gen 1 quirk-laden
Format
RBY OU
No abilities. No held items. No natures. No physical/special split. No EVs. RBY is the franchise stripped to its rawest form — and the meta has been refined for three decades on that minimal base.
At a glance
RBY is the original. None of the customisation systems that define modern competitive Pokémon — abilities, natures, EVs, held items, the physical/special split — exist yet. The format is a stat-and-moveset puzzle.
The minimalism is not a deficit. RBY OU has been actively played for nearly three decades and produces some of the deepest tactical decisions in the franchise — every choice is exposed, every interaction is engine-level, and the meta is one of the most refined in any competitive game.
- ReleasedFebruary 1996 (Japan: Red & Green), September 1998 (US: Red & Blue)
- YellowOctober 1998 (Japan), September 1999 (US)
- RegionKanto
- Type chart15 types — no Steel, no Dark, no Fairy
- Stat system5 stats — HP, Attack, Defense, Special, Speed
- CustomisationDVs (0–15) + stat experience (uncapped). No abilities, no natures, no held items.
- Crit systemSpeed-scaled — base rate 1/512 × base Speed
- Singles tiersUbers, OU, UU (Smogon hierarchy formalised post-Gen 1)
RBY fundamentals
Three structural facts define every Gen 1 game: 15 types, unified Special, and Speed-scaled critical hits. Each one produces meta consequences that no later generation reproduces.
15 types — no Steel, Dark, or Fairy
The Gen 1 type chart has 15 types. Steel and Dark arrived in Gen 2; Fairy arrived in Gen 6. The absence of these three types skews the format heavily toward offense — there is no "wall the Dragon-types" answer (Fairy), no "wall everything" answer (Steel double-resists most types), and Psychic-types in particular have no clean defensive answer.
Unified Special
Pokémon have five stats in Gen 1: HP, Attack, Defense, Special, Speed. The same Special stat handles both special damage output AND special damage absorption. A Pokémon with high Special — Mewtwo, Alakazam, Starmie, Chansey — is correspondingly strong on both sides simultaneously.
Unified Special — 5 stats
Stats
HP, Attack, Defense, Special, Speed
Special use
Single stat used for special damage output AND special-side bulk.
Consequence
High-Special Pokémon are dual-threat — Mewtwo (154 Special) is a special wallbreaker AND a special wall.
Special split — 6 stats
Stats
HP, Attack, Defense, Special Attack, Special Defense, Speed
Specialisation
Each Pokémon has separate offensive / defensive special profiles.
Consequence
Wallbreakers can be high SpA / low SpD; walls can be low SpA / high SpD.
Speed-scaled critical hits
In Gen 1, the base critical-hit rate equals 1/512 × base Speed. A 130-Speed Pokémon (Tauros, Persian) crits at ~25% baseline. A 50-Speed Pokémon crits at ~10%. Combined with the Gen 1 critical-hit damage formula (a clean ×2 multiplier that ignores stat boosts), fast Pokémon produce dramatically more damage variance than later gens — a Tauros Body Slam regularly crits and produces an unexpected KO.
The original 15-type chart
Gen 1 ships with 15 types. Bug is super-effective on Psychic on paper, but a famous engine bug renders Bug effectively unable to threaten Psychic-types — making Psychic the format's structural offensive ceiling.
- Missing types — Steel (added Gen 2), Dark (added Gen 2), Fairy (added Gen 6).
- Psychic dominance — without Dark or Steel, Psychic-types have only Bug and Ghost as super-effective answers. Bug-type moves of the era have low BP (Twineedle is 25 BP × 2; Pin Missile is 14 BP × 2-5) and Ghost is bugged (see below). The result: Mewtwo, Alakazam, Starmie, Exeggutor face few defensive answers.
- The Ghost/Psychic bug — in Gen 1, Ghost-type moves were intended to deal super-effective damage to Psychic Pokémon. A coding error reversed the relationship: Ghost moves do 0 damage to Psychic-types in RBY. The bug was fixed in Gen 2.
- Dragon coverage — Dragon-type moves only deal neutral damage in Gen 1 (Dragon vs Dragon is neutral, not super-effective; Dragon-types take neutral damage from most types).
Battle mechanics baseline
Gen 1's engine has a number of behaviours that no later generation reproduces. Some are intentional design; others are bugs that became part of the format's identity.
≈25%
Tauros crit rate
Speed-scaled — 110 base Speed
2×
Crit damage
Doubled, unaffected by boosts
25%
Paralysis Speed
Quartered Speed
0×
Ghost on Psychic
Engine bug — fixed in Gen 2
| Status | Effect | Notes |
|---|---|---|
| Paralysis | Speed × 0.25 + 25% chance to fail acting | Quartered Speed. |
| Burn | Physical Attack × 0.5 + 1/16 max HP per turn | DoT was 1/16 in Gen 1 (became 1/8 from Gen 2). |
| Freeze | Cannot act until thawed | 0% thaw chance per turn — a frozen Pokémon stays frozen unless hit by a Fire-type move. The franchise's most punishing freeze rule. |
| Sleep | Cannot act for 1–7 turns | Counter persists across switches. Sleep Clause enforced in competitive RBY. |
| Poison | 1/16 max HP per turn | Toxic doubles each turn but resets to 1/16 on switch-out — defining Toxic stalling pattern. |
RBY engine quirks
Gen 1's engine has more quirks than any later generation. Several of them shape the format and have been preserved in the competitive ruleset rather than patched out.
Hyper Beam normally requires a one-turn recharge after use. In Gen 1, if Hyper Beam knocks out the target, the user does NOT need to recharge — the move acts as a free attack on a kill. Defining for Snorlax and Tauros Hyper Beam pivots.
Wrap, Bind, Fire Spin trap the opponent for 2-5 turns AND prevent them from acting. Gen 1 only — later gens let the trapped Pokémon act on their turn. RBY OU's "Wrap stall" used Dragonite or Tentacruel to chain Wraps for guaranteed turn denial.
Substitute creates a 25%-HP decoy — but the calculation rounds DOWN. A 100-HP Pokémon makes a 25-HP Sub; a 99-HP Pokémon makes a 24-HP Sub. Sub also blocks Toxic, Leech Seed, and most secondary effects entirely.
Counter in Gen 1 reflects 2× the last damage the user took, regardless of the move's type. Used on Snorlax to punish predicted physical attackers; particularly devastating against fast Hyper Beam users.
On equal Speed, the franchise rolls 50/50 each turn for who acts first. In Gen 1, both Pokémon roll independently — meaning rare double-action sequences can occur in specific edge cases.
A paralyzed Pokémon scores a critical hit cancels the paralysis Speed reduction for the calculation — meaning a paralyzed Tauros that crits effectively ignores its own Speed drop for that hit.
Focus Energywas supposed to QUADRUPLE the user's critical-hit rate. Due to a bug, it instead QUARTERED it. The move was unusable in Gen 1; fixed in later gens.
No Magic Bounce, no Magic Guard, no Inner Focus — none of the ability-driven status interactions exist. The defensive game is purely typing + Substitute + healing moves.
Dig and Fly make the user invulnerable to most attacks during their charge turn. Some moves break this (Earthquake hits Dig in Gen 2+; Gust hits Fly). The mechanic was different in Gen 1.
Toxic deals stacking damage — turn 1 deals 1/16, turn 2 deals 2/16, turn 3 deals 3/16, etc. The counter resets when the affected Pokémon switches out. Defining engine for stall teams.
Stat experience, DVs, and how stats work
Gen 1 stats are computed differently from every later generation. The pre-EV system used DVs (0–15 hidden values) plus stat experience (uncapped, gainable through battle).
DVs — Determinant Values
Each Pokémon has 4 DVs: Attack, Defense, Speed, and Special (HP DV is computed from the other four). Each ranges 0–15. DVs are randomly assigned at capture and cannot be changed. Modern IVs (0–31) are the Gen 3+ replacement — Gen 1 had half the granularity.
Stat experience
Each stat has a "stat experience" counter that grows when the Pokémon defeats opposing Pokémon. The counter is uncapped at the engine level, but maxes out at 65,535 per stat (giving the maximum stat-experience contribution). Pre-Gen 3, this was the customisation system — competitive Pokémon were "trained" by grinding wild encounters to max stat experience in specific stats.
No natures, no abilities, no items
Gen 1 has no nature system (introduced in Gen 3), no ability system (Gen 3), and no held items (Gen 2). A Pokémon's competitive identity is entirely determined by species + DVs + stat experience + moveset.
Defining moves of RBY
The Gen 1 movepool is small and the meta-defining moves are correspondingly few. Several of these moves were nerfed or removed in later gens — RBY OU is partly defined by what stayed legal here that didn't survive.
Normal 85-BP physical attack with a 30% paralysis chance. STAB on Tauros / Snorlax / Chansey. The most-used move in RBY OU — paralysis pressure shapes every game.
Normal 150-BP attack that requires recharge — except on KO, where Gen 1 skips the recharge. Defining late-game finisher for Tauros and Snorlax.
Ground100-BP physical attack with no drawback. The franchise's archetypal Ground-type STAB option from Gen 1 onward.
Electric 95-BP special attack with 10% paralysis chance. Defining special STAB for Zapdos, Jolteon, Starmie.
Water 95-BP special attack. Defining Water STAB; distributed broadly via HM.
Ice95-BP special attack with 10% freeze chance. The freeze rate combined with Gen 1's "no thaw" rule made Ice Beam a dangerous coverage option.
Psychic90-BP special attack with 10% chance to lower SpD. Distributed broadly. Combined with Gen 1's Psychic-dominance, near-universal coverage.
Normal15-BP physical attack that traps the target for 2-5 turns AND prevents them from acting. Combined with Dragonite's 134 Atk, produced one of RBY OU's defining stalling patterns.
Poison status move that badly poisons the target. Toxic damage stacks each turn; the counter resets on switch-out. Defining stall engine.
Competitive formats
RBY OU is one of the franchise's most enduring formats. Smogon's tier hierarchy was formalised post-Gen 1 but the OU competitive meta has been continuously played since the late 1990s.
Tier 1
OU — OverUsed
6v6 Singles. Most-played retro format on Smogon. Mewtwo and Mew banned to Ubers; the Tauros / Snorlax / Chansey / Starmie / Exeggutor / Alakazam core defines the meta.
Restricted
Ubers
Hosts Mewtwo and Mew. Ubers in Gen 1 is small — only two Pokémon are formally banned from OU.
Tier ladder
UU
Lower Singles tier. Less actively played than OU but follows the standard Smogon usage-drop pattern.
Specialty
Smogon Tour / SPL
RBY OU is one of the franchise's most-played retro formats. Smogon Tour, SPL, and several long-running tournaments keep the format alive nearly 30 years after release.
Ruleset
Sleep Clause + Freeze Clause
Gen 1's 0% thaw rule made Freeze Clause necessary — competitive RBY enforces "only one opposing Pokémon may be frozen at a time" in addition to the standard Sleep Clause.
History
The format's longevity
RBY OU has been continuously played at a competitive level for over 25 years. Few competitive games of any genre have a format with that kind of unbroken activity.
Defining bans
RBY OU's banlist is the smallest of any modern format. Two Pokémon — Mewtwo and Mew — are banned. Beyond that, the format relies on the natural meta to constrain options.
Notable Gen 1 OU bans
| Pokémon | Why it was banned |
|---|---|
| Mewtwo | 154 Special + 130 Speed + universal coverage. With Gen 1's unified Special, Mewtwo is simultaneously the format's strongest wallbreaker AND strongest special wall. Permanent Ubers from Gen 1 onward. |
| Mew | 100 stats across the board + universal moveset access. Mew can run any role and learn nearly any TM. Permanent Ubers. |
Several Pokémon have been suspect-tested over the format's long history but stayed in OU — Tauros for raw Body Slam dominance, Chansey for special-side dominance, Snorlax for Hyper Beam recharge skip, Alakazam for special wallbreaking. The format has stayed remarkably stable.
Two banned Pokémon. Twenty-five years of competitive play. RBY OU is the most refined, most stable competitive format the franchise has produced.
Iconic Pokémon of the era
The RBY OU big six — Tauros, Snorlax, Chansey, Starmie, Exeggutor, Alakazam — define the format. Almost every game features all six.
Singles — RBY OU
Tauros
Wallbreaker · Late-game cleanerBody Slam — Hyper Beam — Earthquake
The defining Pokémon of RBY OU. Body Slam (paralysis pressure) + Hyper Beam (recharge skip on KO) + Earthquake + Blizzard. 110 Speed = ~21% crit rate. Tauros wins more games than any other Pokémon.
Snorlax
Wallbreaker · Hyper Beam pivotBody Slam — Hyper Beam — Earthquake
Body Slam paralysis pressure + Hyper Beam recharge skip + Earthquake + Counter / Self-Destruct. Mixed bulky offence — 160 HP / 110 Atk / 65 Def / 110 Special / 30 Speed.
Chansey
Special wall · ClericSoft-Boiled — Thunder Wave — Seismic Toss
255 HP / 5 Atk / 5 Def / 105 Special / 50 Speed. The franchise's premier special wall, especially under Gen 1 unified-Special rules. Soft-Boiled + Thunder Wave + Seismic Toss + Ice Beam.
Starmie
Special pivot · RecoverySurf — Thunderbolt — Recover
115 Speed + 100 Special + 75 HP. Surf + Thunderbolt + Recover + Blizzard / Psychic / Thunder Wave. The format's archetypal special pivot — fast, bulky enough to take a hit, and self-healing.
Exeggutor
Special wallbreakerPsychic — Sleep Powder — Explosion
95 HP / 95 Atk / 85 Def / 125 Special / 55 Speed. Psychic + Sleep Powder + Explosion + Stun Spore. Defining Psychic-type wallbreaker; uses Sleep Powder to disable a counter then Explosions for guaranteed offensive value.
Alakazam
Special wallbreakerPsychic — Recover — Thunder Wave
55 HP / 50 Atk / 45 Def / 135 Special / 120 Speed. Psychic + Recover + Thunder Wave + Seismic Toss. Frail but the format's strongest special attacker; Gen 1's Psychic dominance gave it few defensive answers.
Rhydon
Physical wallEarthquake — Body Slam — Substitute
105 HP / 130 Atk / 120 Def / 45 Special / 40 Speed. Earthquake + Body Slam + Rock Slide + Substitute. The format's premier physical wall; Ground/Rock typing checks Tauros and Snorlax Body Slam pressure.
Slowbro
Special wall · WallbreakerSurf — Amnesia — Rest
95 HP / 75 Atk / 110 Def / 100 Special / 30 Speed. Amnesia (raises Special by 2 stages in Gen 1) + Surf + Rest + Thunder Wave. Pre-split, Amnesia made Slowbro one of the most reliable setup wincons.
Zapdos
Special pivotThunderbolt — Drill Peck — Thunder Wave
90 HP / 90 Atk / 85 Def / 125 Special / 100 Speed. Thunderbolt + Drill Peck + Thunder Wave + Agility. Defining Electric-type wallbreaker; the only Electric/Flying defensive pivot of the era.
Lapras
Mixed wall · CoverageSurf — Blizzard — Body Slam
130 HP / 85 Atk / 80 Def / 95 Special / 60 Speed. Surf + Blizzard + Body Slam + Sing. The era's premier mixed Water/Ice wall; Sing as a niche sleep option.
Where to go from here
The above is the static reference for Gen 1. The current state of any of its formats — top usage, recent tournament results — lives in the rest of Pokékipe.
- Live meta data — Pokémon stats, Team Builder, Timeline.
- Terminology — every term used above is defined in the Competitive Glossary.
- Workflow — the Core Mechanics guide covers EVs, IVs, natures, speed tiers — note that most of these systems do not apply to RBY (no natures, no abilities, no held items, DVs instead of IVs).
- Adjacent eras — Gen 2 — Gold & Silver covers the Steel/Dark addition, the Special split, and held items — the systems that built on Gen 1's foundation. Each later generation has its own page accessible from the Guides hub.