You need a Pokemon - SoulSilver Version (USA) [DS] ROM. The file should be approximately 128 MB and have an .nds extension. Look for a ROM with a checksum matching the original release (often hash AD9B9C0F for the US version).

My starter is a Legendary, but it won’t obey me because I have no badges. Solution: This is correct behavior. In Gen IV, traded Pokémon (and randomized starters are flagged as "met at level 5") obey based on badges. If you randomize a level 5 Mewtwo, it requires the same badges as a level 5 Pidgey. It will obey.

Check the box labeled "Prevent Broken HM Progression." This is the hallmark of a modern randomizer. It will verify that at least one catchable Pokémon on every route can learn the HM required for the next area.

You need a clean, unmodified Pokemon - Soul Silver Version (USA).nds file. Verify the MD5 checksum if possible. A "bad dump" will cause the randomizer to crash.

For those unfamiliar, a Randomizer ROM is a modified version of a game that shuffles various elements, such as Pokémon species, moves, items, and even character appearances. This randomization creates a unique experience each time the game is played, offering a fresh challenge and a new way to explore the Pokémon universe.

The core of the randomizer. The updated version distinguishes between: