Mewtwo is the final boss of Pokémon Stadium. It only appears once you have won every tournament in the game, and defeating it rolls the credits, changes the title screen and opens up Round 2. The battle is unusual: you can send in six Pokémon while it only has one, but this level 100 Mewtwo takes hits, hits hard and heals itself.
Making Mewtwo appear
Two conditions must be met in Round 1:
- win the ten Stadium trophies: the Pika Cup, the Petit Cup, the four divisions of the Poké Cup and the four divisions of the Prime Cup;
- complete the Gym Leader Castle, all the way to the victory over the Rival.
Once both goals are achieved, Mewtwo’s silhouette appears in the sky above the stadium on the mode selection screen. Move the cursor all the way up to select it: this is the “Versus Mewtwo” tournament.
Battle rules
| Rule | Versus Mewtwo |
|---|---|
| Number of Pokémon | Up to six, against a single opponent |
| Levels | From 1 to 100, with no total limit |
| Rental Pokémon | Yes, the Prime Cup ones (level 100) |
| Your Game Boy Pokémon | Yes, via the Transfer Pak |
| Sleep Clause and Freeze Clause | No: nothing stops you from putting Mewtwo to sleep or freezing it |
| Self-KO Clause | Yes: if your last Pokémon faints at the same time as Mewtwo (Explosion, Self-Destruct), you lose |
The opposing Mewtwo
| Round 1 | Round 2 | |
|---|---|---|
| Level | 100 | 100, stats pushed to the maximum |
| Moves | Psychic, Blizzard, Thunderbolt, Rest | Psychic, Amnesia, Thunderbolt, Rest |
| PP Up | On all four moves | On its two offensive moves |
Psychic is its main weapon: in Generation I, the Psychic type has almost no exploitable weakness, and its Special stat, which is used for both offense and defense, is the highest in the game. Blizzard and Thunderbolt cover the Pokémon that resist Psychic. When its HP drops into the yellow or red, it uses Rest: it recovers all its HP and status conditions, but falls asleep for two turns. In Round 2, Amnesia replaces Blizzard and lets it double its Special, which makes special attacks almost useless after a turn or two.
The strategy that works with rentals
There is no point trying to beat Mewtwo head-on: it is faster and more powerful than almost every rental Pokémon. The most reliable plan comes down to two steps.
1. Paralyze it
Electrode is the best opener: it is one of the few rental Pokémon faster than Mewtwo in Round 1, and it knows Thunder Wave and Flash. Use Thunder Wave on the very first turn. Once paralyzed, Mewtwo has its Speed cut to a quarter and loses one turn in four. If Electrode is still standing, follow up with Flash to lower its accuracy.
If Mewtwo sleeps off its paralysis with Rest, start over: keep a second Pokémon with Thunder Wave in reserve, such as Magneton, which also has Flash and Supersonic.
2. Knock it out in one hit
In Generation I, one-hit KO moves (Fissure, Guillotine, Horn Drill) automatically fail if the user is slower than its target. That is why paralysis comes first: once Mewtwo is slowed down, slow Pokémon like Rhydon or Kingler become faster than it, and every turn gives them a one-in-three chance of winning the battle. Mewtwo is not immune to these moves.
| Pokémon | Types | Lv. | Rental moves |
|---|---|---|---|
| Electrode | Electric | 100 | Thunder, Thunder Wave, Swift, Flash |
| Magneton | Electric | 100 | Thunder Wave, Supersonic, Thunder, Flash |
| Rhydon | Ground/Rock | 100 | Horn Attack, Fissure, Earthquake, Thunder |
| Kingler | Water | 100 | Crabhammer, Toxic, Strength, Guillotine |
| Pinsir | Bug | 100 | Slash, Seismic Toss, Toxic, Guillotine |
| Diglett | Ground | 100 | Fissure, Earthquake, Sand Attack, Slash |
- Electrode and Magneton: paralysis, then Flash to reduce Psychic’s accuracy.
- Rhydon and Diglett: Fissure. Rhydon takes hits better and also has Thunder.
- Kingler and Pinsir: Guillotine. Pinsir also has Seismic Toss, a decent physical attack once Mewtwo’s Defense has been lowered.
With six Pokémon and paralysis in place, the chance of landing none of the one-hit KO moves before losing your whole team is low. If the battle goes badly in the first few turns, nothing stops you from giving up and starting again: there is no penalty.
Variations
- Lowered accuracy and Defense: six Flashes make Psychic very unreliable, and three Screeches (Persian, Meowth, Tentacruel or Muk among the rentals) crush its Defense; all it takes then is one powerful physical attack, or even an Explosion or a Self-Destruct (Onix, Exeggcute), keeping the Self-KO Clause in mind.
- Confusion and Leech Seed: Confuse Ray (Haunter, Ninetales, Magmar) and Leech Seed (Venusaur, Exeggcute) stay active after Rest. Combined with paralysis, they make Mewtwo lose many turns.
- Ditto: it copies Mewtwo, moves included. In Round 1, it can try to freeze it with Blizzard; in Round 2, it also has Amnesia. The gamble is risky, because the copy has Ditto‘s HP.
With your own Pokémon
Your Pokémon from Red, Blue or Yellow have a big advantage over the rentals: their effort points (the “stat experience” of the first generation), built up over battles and vitamins, make them considerably sturdier. Your own Mewtwo, a Mew that has learned Swords Dance, a Chansey with Light Screen or a Snorlax with Self-Destruct change everything.
In Round 2
To face it again, you have to win all the trophies and the Castle a second time, this time in Round 2. The second Mewtwo is harder for two reasons: its stats are maxed out, so no rental Pokémon outspeeds it, and Amnesia neutralizes special attacks. Paralysis remains the key: an Electrode that survives a Psychic (without a critical hit) can still land Thunder Wave, as long as Mewtwo hits first without finishing it off. Prepare two or three Pokémon able to paralyze, then the same battery of one-hit KO moves.
In the American version, defeating Mewtwo in Round 2 unlocks stickers hidden in the Gallery, a mode absent from the European version (see the differences between versions).
What comes next?
Beating Mewtwo in Round 1 rolls the credits and takes you back to a modified title screen. Round 2 is then activated from the main menu with the C-Right button. The rewards that follow are detailed on our rewards page, and the game’s most famous secret in Surfing Pikachu.
