How to get the Regis (Ruby & Sapphire)

Regirock

1. Go to the south part of the desert. There will be a small cave.
2. From here, go down two steps then right two steps.
3. Use Strength. A door will open and you can catch Regirock!

Regice

1. Surf to Route 105. There will be another cave.
2. Go to the braille words and press A.
3. Wait for two full minutes. Then, a door will open so you can catch Regice!

Registeel

1. Go to the cave on Route 120.
2. Go to the center of the cave, then use fly.
3. A door will open to allow you to catch Registeel!

Note-Before you do this, you have to unlock the Regis.