By playing Pokemon Emerald, you can catch many Legendary Pokemon. This tutorial shows you how to spot three of them without using any tricks or 'cheat code'.
Steps
Method 1 of 3: Kyogre
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Step 1. Go to the 'Weather Center' and enter inside
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Step 2. Go up to the second floor and talk to the scientist on the far left
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Step 3. Follow the path indicated by the scientist and use the 'Sub' move to access a small submerged cave
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Step 4. At the end of the path you will find Kyogre at level 70 waiting for you
Method 2 of 3: Rayquaza
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Step 1. Return to the 'Tower of Heaven' using a 'Road Bike'
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Step 2. Climb to the top of the tower and fight Rayquaza, his level will be 70
Method 3 of 3: Groudon
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Step 1. Head to the 'Weather Center' and ask the scientist you spoke to to find 'Kyogre'
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Step 2. Find the cave he told you about
Inside, Groudon will be waiting for you at level 70.