Generation 1 OU (RBY) — Singles Format Reference
RBY OU is the franchise's longest-living competitive format — actively played for over 28 years. The big six (Tauros, Snorlax, Chansey, Starmie, Exeggutor, Alakazam) appear on almost every team. The format has only TWO banned Pokémon — Mewtwo and Mew.
Cartridge
Red / Blue / Yellow
Type
6v6 Singles
Status
Frozen tier · 28+ years played
Era
Original
Twenty-eight years of continuous play, two banned Pokémon, and a meta most players consider the most refined in any competitive game. RBY OU is what happens when a community plays one format for three decades.
At a glance
RBY OU 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, played at extreme depth.
The minimalism is not a deficit. RBY OU has been actively played since the late 1990s and remains one of the most-played retro formats on Pokémon Showdown. Smogon Tour, Smogon Premier League, and the World Cup all run RBY OU continuously.
- Format type6v6 Singles, all six brought to battle
- Mechanics15 types only, unified Special, Speed-scaled crits, no held items, no abilities
- StatusFrozen — meta stable since Gen 2 succession; played continuously since the late 1990s
- Where it's playedPokémon Showdown ladder + retro tournaments. Live tier page: /rby/ou.
- Sister formatUbers — hosts Mewtwo and Mew only
Format rules
RBY OU applies the standard Smogon Singles clauses, plus a Freeze Clause specific to Gen 1's engine — the franchise's 0% thaw rate makes freezing as punishing as KO.
| Clause | Effect |
|---|---|
| Sleep Clause | Only one opposing Pokémon may be put to sleep at a time. |
| Species Clause | Each team can only carry one of any given species. |
| Freeze Clause | Only one opposing Pokémon may be FROZEN at a time. Specific to Gen 1's 0% thaw rate. |
| Evasion Clause | Evasion-boosting moves and items are banned. |
| OHKO Clause | Sheer Cold, Fissure, Horn Drill, Guillotine are banned. |
| Endless Battle Clause | Battle states that cannot end are forbidden. |
| No abilities | Abilities don't exist in Gen 1. |
| No held items | Held items don't exist in Gen 1. |
Banlist
RBY OU has the smallest banlist of any modern competitive format. Two Pokémon are banned. Beyond that, the natural meta constrains team-building.
Banned Pokémon in RBY OU
| 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. |
| Mew | 100 stats across the board + universal moveset access via TM. Mew can run any role. 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.
The big six
Six Pokémon define RBY OU. They appear on almost every competitive team and the format's strategic depth lives in how they interact.
Tauros: 75/100/95/70/110. Body Slam (paralysis pressure) + Hyper Beam (recharge skip on KO) + Earthquake + Blizzard. 110 Speed = ~21% baseline crit. The format's defining offensive engine — wins more games than any other Pokémon.
Snorlax: 160/110/65/65/30. Body Slam paralysis pressure + Hyper Beam recharge skip + Earthquake + Counter / Self-Destruct. Mixed bulky offence — the format's most flexible Pokémon.
Chansey: 250/5/5/105/50. Soft-Boiled + Thunder Wave + Seismic Toss + Ice Beam. The franchise's premier special wall under Gen 1 unified-Special rules.
Starmie: 60/75/85/100/115. Surf + Thunderbolt + Recover + Blizzard / Psychic / Thunder Wave. The format's archetypal special pivot — fast, bulky enough to take a hit, and self-healing.
Exeggutor: 95/95/85/125/55. Psychic + Sleep Powder + Explosion + Stun Spore. Defining Psychic-type wallbreaker; uses Sleep Powder to disable a counter then Explosions for guaranteed offensive value.
Alakazam: 55/50/45/135/120. Psychic + Recover + Thunder Wave + Seismic Toss. Frail but the format's strongest special attacker; Gen 1's Psychic dominance gave it few defensive answers.
RBY engine quirks
Gen 1's engine has more competitively-relevant quirks than any later generation. Several of them shape RBY OU and have been preserved as part of the format's identity rather than patched out.
- Hyper Beam recharge skip — 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. Defining for Tauros and Snorlax late-game cleaning.
- Wrap loop — 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.
- Toxic counter — Toxic stacks each turn (1/16 → 2/16 → 3/16 …) and resets when the affected Pokémon switches out. Defining stalling pattern.
- Speed-scaled critical hits — base crit rate equals 1/512 × base Speed. A 130-Speed Pokémon (Persian) crits at ~25%; a 50-Speed Pokémon at ~10%. Combined with Gen 1's ×2 crit damage, fast Pokémon produce dramatically more variance than later gens.
- 0% freeze thaw — frozen Pokémon stay frozen unless hit by a Fire-type move. Freeze Clause exists specifically for this reason.
- Counter / Mirror Coat — Counter reflects 2× the last damage taken regardless of move type. Used on Snorlax to punish predicted physicals, particularly Hyper Beam users.
Archetypes
RBY OU's archetypes are simpler than later gens — fewer Pokémon, fewer items, no abilities. Most teams are variations on the big six core with one or two flex slots.
Standard
Big Six Balance
Tauros + Snorlax + Chansey + Starmie + Exeggutor + Alakazam. The canonical RBY OU team. Variations swap one slot for Rhydon, Slowbro, Zapdos, Lapras, or Gengar.
Bulky Offense
Snorlax + 5
Snorlax Body Slam pressure + Tauros + 4 supporting Pokémon. The most-played offensive archetype.
Stall
Wrap stall
Dragonite or Tentacruel Wrap + Toxic chip + Chansey for special walling. Niche but viable — RBY-specific stalling pattern.
Specialty
Sleep Powder lead
Lead with ExeggutorSleep Powder, sleep-stall the opponent's sleep slot, then Explosion for momentum. Defining lead pattern.
Specialty
Belly Drum equivalent
Snorlax Amnesia + Surf / Hydro Pump (Gen 1 unified Special makes Amnesia +2 Special). Setup wincon variant.
Team-building roles in RBY
The seven structural roles map onto RBY OU but with significant differences. Many roles don't exist (no held items, no abilities, no hazards beyond Spikes which arrives Gen 2).
Stealth Rock, Spikes, Toxic Spikes, Sticky Web all arrive in later gens. Gen 1 has no entry hazards — chip damage comes from Toxic, paralysis Body Slam, and Wrap loops.
No hazards to remove. Defog and Rapid Spin don't exist yet.
Body Slam (30% paralysis on most Pokémon) is the format's primary speed control. Thunder Wave on Chansey / Alakazam / Starmie. No Choice Scarf yet.
Without abilities (no Magic Guard, no Natural Cure), defensive Pokémon eat status. Heal Bell / Aromatherapy don't exist. Status-stalling is part of the format identity.
U-turn, Volt Switch, Baton Pass don't exist as offensive pivots. Switching is purely sacrificial in RBY.
Choice Band doesn't exist (Gen 3). Wallbreakers run raw stats + STAB. Tauros Body Slam + Hyper Beam, Snorlax Body Slam + Hyper Beam + Earthquake, Alakazam Psychic.
What makes RBY OU different
RBY OU is structurally unlike every later format. The differences are categorical, not gradient — half the modern competitive frameworks don't apply at all.
2
Banned Pokémon
Smallest banlist in any modern format
28+
Years played
Longest-living competitive format
0
Hazards
No Stealth Rock / Spikes / Toxic Spikes
- Two banned Pokémon — Mewtwo and Mew. The format constrains itself naturally; tier councils have rarely needed to act.
- 15 types — no Steel, no Dark, no Fairy. Psychic-types have few structural answers; Bug is super-effective on paper but no Bug move has high BP; Ghost has the famous "0 damage to Psychic" engine bug.
- Unified Special — high-Special Pokémon (Mewtwo, Alakazam, Starmie, Chansey) are dual-threat. The same stat handles output AND absorption.
- Speed-tied crits — Tauros / Persian / Aerodactyl crit at ~20-25% baseline. Fast Pokémon produce more damage variance than any later gen.
- Engine quirks — Hyper Beam recharge skip, Wrap loops, Toxic counter, 0% freeze thaw — each shapes specific matchups in ways no later gen reproduces.
How to get started
RBY OU has the longest tournament archive of any Singles format. Smogon's analyses are exhaustive; the meta is the most refined of any single generation.
- Read Smogon's RBY OU tier page — banlist locked since the late 1990s, decades of community wisdom.
- Build the big six first — Tauros + Snorlax + Chansey + Starmie + Exeggutor + Alakazam is the canonical team. Play it before customising.
- Learn the engine quirks — Hyper Beam recharge skip, Wrap loops, Toxic counter rules, Speed-tied crits. The format's skill ceiling lives in these mechanics.
- Copy a sample team — Smogon's vetted RBY OU samples are stable.
- Ladder Pokémon Showdown — RBY OU has an active retro ladder. Tournament play continues via Smogon Tour, SPL, and the World Cup of Pokémon.
Where to go from here
The above is the static reference for RBY OU. Live frozen-tier data lives in the rest of Pokékipe.
- Live tier data — /rby/ou for RBY OU usage and Pokémon stats.
- Mechanics — Gen 1 — Red & Blue covers the original 15-type chart, unified Special, Speed-tied crits, and engine quirks in detail.
- Adjacent formats — GSC OU covers the format that succeeded RBY and added Steel + Dark types, the Special split, and held items.
- Tournament history — Timeline tracks Smogon Tour, SPL, and World Cup RBY OU results.