Introduced in Pokemon X and Y, this much-loved feature makes a return in the Festival Plaza. Just like in previous games, Wonder Trade can be accessed when connected to the Internet.
How Wonder Trade works is that you select a Pokemon to trade away and the game randomly assigns you a trade partner from anywhere in the world who happens to be using Wonder Trade at the same time.
Both of you don't know what Pokemon you're getting from the other until the trade actually occurs. There is also absolutely no feedback involved in the process, so don't expect any negotiations or anything like that.
Wonder Trade is great fun because you never know what Pokemon you're going to get and it's also incredibly simple to set up, with no fuss at all.
Good in Theory?
It's not without its downsides though. Because of the anonymity, there is no benefit to trading away actually good Pokemon, so chances are you'll be receiving junk most of the time.
However, as they say, somebody's junk can be somebody else's treasure. Perhaps this junk is a Pokemon you don't yet own. Or maybe it's a reject Pokemon from somebody's breeding project that you can incorporate into your own breeding project.
Even if you do miraculously get something good, that's when your alarm bells should be ringing. While there are some very kind people in the world, the chances of you getting a shiny Pokemon or Level 100 6 IV Pokemon for real is astronomically slim.
Should you receive such a Pokemon, you can confidently assume that it's cloned (because you don't lose anything that you clone) or, worse, outright hacked. Now, there are no adverse effects of owning cloned or hacked Pokemon, especially if they're for your personal collection, but it's something to keep in mind.
If you're intending to participate in official competitions, we recommend not using Pokemon obtained from Wonder Trade. Instead, try to use your own Pokemon or Pokemon traded from people you actually know.