Ok for this you will need TM 28(Dig), HM 03(surf), HM 06(rock smash, HM 05(flash), HM 08(dive), a Wailord (capture wailmer with super rod and evolve at level 40), and a relicanth (catch when you dive underwater, hard to find and hard to catch). Once you are all set, fly to pacificlog town, go to the left part (the fast currents) surf, and find your way to a little diving spot in the middle of route 134. Once you are there, use dive, keep going straight til the end, you will find brail writing on the wall, go up to it and dive back up to the surface from there. You are now here, go to the very top where you'll see 3 brail writings on the wall, stand infront of the middle one and use dig.Now that you opened the passage enter and walk straight up, stand infront of the middle baril writing again, put wailord as your first pokemon and relicanth as your last in your party then click on the writing then after the place will start shaking, thats when the 3 regi doors open.
|Regice||route 105, north of dewford town, inside the cave stand infront of the brail writing then walk around 1 lap around the cave. (stay against the wall)|
|Regirock||Go to the desert north of mauville city find the cave in the south end of the desert. inside the cave from the brail writing go left,left,down,down then use rock smash.|
|registeel||west of lilycove city at then end go up on the little mountain with the water and berries then go up north, in the cave walk into the middle of the cave and use flash.|