Encounter Randomizer Betain Pokémon Polished Crystal

Rewrite every wild encounter in the game from a seed you choose: grass and caves, surfing, fishing, headbutt trees and smashable rocks alike. Optional settings also rewrite species data, moves and TM/HM compatibility. Your ROM is patched in your browser — it is never uploaded, and nothing is stored.

Your ROM stays on your device
The file is read and rewritten in your browser. Nothing is uploaded, and no copy is kept. You keep the original; this produces a second file next to it.

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A seed is picked for you. Same seed, same settings, same game, so a friend’s seed gives you their exact run -- or send them the settings link below and they get yours.

Start from a preset

Pick one, then change anything below to make it your own.

Wild Pokémon

Every species gets at least one wild slot somewhere, so you can always finish the dex. Legendaries keep their own encounters. Every form counts as a Pokémon of its own too: a Pikachu with a surfboard, a spotty Magikarp or an icy Alolan Vulpix can turn up like any other Pokémon.

How Pokémon are swapped
Which Pokémon show up
Wild Pokémon levels

Higher wild levels for a harder run: +50% turns a level 10 into a 15. Nothing goes past 100, and the spots where levels already grow with your badges stay as they are.

The Pokémon themselves

These change what a Pokémon is like, not where it lives, so they apply to every Pokémon of that kind: wild ones, trainers’ and your own. Regional forms such as Alolan Vulpix keep their usual stats, types and abilities.

Base stats

New base stats for every Pokémon, pulled from other Pokémon -- HP, Attack, Defense, the lot. A Caterpie can come out hitting harder than a Tyranitar.

Types

Types get shuffled around. Pikachu might come out Water and Ground, Gyarados Electric.

Abilities

Abilities get shuffled around, hidden ones included.

Wild held items

Shuffles what wild Pokémon can be holding when you catch them.

Moves

This changes the moves themselves, so it applies everywhere: wild Pokémon, trainers and your team.

Move type

Move types get shuffled around -- Ember might come out a Water move. Struggle, Metronome and Hidden Power stay put.

What Pokémon can learn

TMs and move tutors

Changes which TMs and move tutor moves each Pokémon can learn. Same number each, just different ones. HMs stay put.

Every HM learnable

Every Pokémon can learn all six HMs, so nothing gets stuck behind a Cut tree or a stretch of water.

Every TM, HM and move tutor still teaches the same move. Only who can learn it changes.

Starters

The three Poké Balls in Professor Elm’s lab. Your rival and Lyra take the matching Pokémon from your set: the ball the game gives them still depends on the one you pick, and each battle has that ball’s Pokémon at the same stage of its evolution line, with the moves the game gives it at that level. Held items stay the original starter’s.

Starter Pokémon

Random deals you three different starters. Pick my own lets you choose each of the three.

Starter held item

Each starter gets a random item to hold.

A ball can give any form this game lists for its Pokémon, such as a Pikachu with a surfboard or an Alolan Rattata, and the spoiler log names the form it gave. A regional form brings its own types and stats. Elm still asks “You’ll take Cyndaquil?” by the original name, and the ball still shows the original Pokémon’s picture and plays its cry.

Trainers

Trainer parties

Keep types swaps each trainer’s Pokémon for one of the same type, and a themed team -- every gym leader, the Elite Four -- keeps its theme. Fully random swaps for anything in the pool and uses the same swap everywhere, so leaders and the Elite Four lose their type. Levels and held items stay either way, and a Pokémon with a hand-picked moveset gets the moves its new species knows at that level. The few whose level grows with your badges keep theirs. Change your starters and the rival’s and Lyra’s still come from your set.

Send the settings link to a friend and they get the same seed and settings, so their game comes out exactly like yours. They still need their own ROM.

Want to see where a species ends up instead? The Encounter Finder lists the unmodified game’s locations for every Pokémon.