Pokémon Mystery Dungeon: Blue Rescue Team Tips

Recruiting the legendary pokemon
To recruit the legendary pokemon like Moltres or Groudon, First you have to go threw the dungeon they were in and battle them. When you do have two or less pokemon on your team. When you defeat them, they will want to join you. Afterwards you will get their friend area and you can use them anywhere. Since they are so big you can only have one on your team at a time.