Game Mechanics

Stat Experience

Every knockout silently grants Stat Exp in all five stats, equal to the defeated species' base stats. The cap is 65,535 per stat; at level 100 a maxed stat is worth about +63 points. Vitamins (HP Up, Protein and the rest) add 2,560 each, capped at 25,600 per stat.

There is no 510-point total cap in Generation I. You can max every stat on every Pokemon - it just takes grinding.

DVs (Determinant Values)

Gen 1's IVs, on a 0-15 scale. Attack, Defense, Speed and Special are rolled randomly; the HP DV is derived from the low bits of the other four. Each DV point is worth roughly 2 stat points at level 100. They are fixed at the moment of the encounter, invisible, and cannot be changed.

One practical consequence: a level gained from a Rare Candy recalculates stats from your current Stat Exp, so candying an untrained Pokemon wastes growth it would otherwise have banked.

Generation I has a single Special stat used for both special attack and special defense. A Pokemon with high Special both hits hard with Thunderbolt and shrugs off Surf.

That is why Alakazam (135 Special), Mewtwo (154) and Tentacruel (100) are so dominant, and why the Volcano Badge's Special boost is quietly the best of the four badge boosts.

Critical hits scale with BASE SPEED

Normal crit chance is BaseSpeed / 512. High-crit moves - Slash, Razor Leaf, Crabhammer, Karate Chop - use BaseSpeed / 64, which for a fast Pokemon is effectively always. Persian, Dugtrio and Electrode crit constantly, and a Persian with Slash crits nearly every turn.

Crits ignore all stat modifiers, both yours and theirs, and use level x2 in the damage formula.

Focus Energy is bugged: it quarters your crit rate instead of quadrupling it. Never use it.

Badge boosts

Boulder = Attack, Thunder = Speed, Soul = Defense, Volcano = Special, each x9/8. The badge-boost glitch re-applies those multipliers every time a stat stage changes, so repeated Swords Dance or Agility snowballs a stat far beyond the intended value.

• Ghost does nothing to Psychic. A bug - it was meant to be super effective.
• Hyper Beam does not recharge if it knocks the target out or breaks a Substitute. This is what makes Tauros, Snorlax and Dragonite elite.
• Gust and Karate Chop are Normal-type in Generation I.
• Wrap, Bind and Fire Spin lock the opponent out of moving for as long as they keep connecting.
• Frozen Pokemon never thaw on their own - only a Fire-type hit, an Ice Heal or Haze frees them. Blizzard was 90% accurate. Do the maths.
• Sleep costs the wake-up turn as well as the sleeping turns.
• Any "100% accurate" move still misses 1 time in 256.
• Toxic and Leech Seed share a damage counter, so together they stack into escalating damage.
• Recover and Softboiled fail outright when the HP deficit is exactly 255 or 511.
• Psychic is the dominant offensive type: nothing resists it except Psychic.