You CANT. MWAHAHAHAHAHA. -coughs-
go to sandgem town, in dawns house a girl there will tell you routes where rare Pokemon can be found, hopefuly she will say a route where beldum can be found
you can catch beldum at route 228 with poke'radar
if you wanna catch beldum it a mass outbreak on route 228
you use a pokeball in Pokemon dimand and pearl you can not get beldum only in Pokemon emerald you have to beat the elite four go to wallys house in mousdeep there will be a poke ball click on it and you have a beldum to get beldum in fire red and leaf green trade it in Pokemon ruby and Sapphire can get beldum too what are you talking about,you CAN catch beldum in diamond and pearl.you have to get the national pokedex and talk to your rivals sister in her house and you can catch it in a swarm Unfortunatly, it shares the " hardest to catch Pokemon" award with Skarmory"-thy both have 2.98 percent catch rates. Arceus is easyer to catch.
Train it to level 20
Level 33.
Pokemon like Anorith, Lileep, Beldum, those kind.
Steven Stone will give you a Beldum in exchange for a Forretress.
check in the pokedex
ye after you beat the elit 4 go to steavens house in mossdeep city this goes for emerald and ruby 2 lol
You get Beldum for free, from Steven after you finish the Pokemon League, go to Stevens house and the ball will be on the table.
I don't think you need ruby at all. All you need is national dex andtalk to the little girl in sandgem town. Eventually she will say that there are lots of beldum in the desert between stark mountain and the peaceful place (i think its the relax area?) You should catch one on about lv 52