I hope this isn't too problematic of a question, since technically it would work the same way on a real Gameboy Advance...
A friend of mine and I have gotten into playing Emerald on Android. However, since he has way more free time than I do, I always end up under him by ten or so levels. Another friend of mine who is more into Pokemon than the both of us suggested that Gen 3 games had a way to battle each other locked at level 50. However, I can't seem to find that.
When we fought on the Android, the Wireless Adapter did not function (for all intents and purposes, so you don't whine that this is our fault for emulating it, just pretend I said "but we didn't have two Wireless Adapters") but the Link Cable worked, so we could not use the Union Room but the Cable Club worked (we even had a few battles in it that worked like a charm, but like I said I got tossed aside by 65+ level mons). There, the only options were Single Battle, Double Battle, and Multi Battle; none of these offered the option to limit the levels. I asked my friend about this, and he decided it must have been in the Union Room. Eventually I found out that VBA had a working Wireless Adapter (or just pretend I said "I borrowed someone else's adapters") and I decided to test out battling there. However, when I tried to challenge myself, it told me I needed Pokemon that were level 30 or below.
So, is my friend wrong about Gen 3 having a 50-locked multiplayer battle, or is there something we're both missing? Is level-locked fighting a Gen 4 thing? Are we wasting our time with Gen 3 (even if we did have our own Gameboys) and should blow $400 we don't have on fairy Gardevoirs?