I'm aware that this perhaps could be posted in New Recruits but this is somewhat a discussion about the game.
Anyway, a few updates ago, this was added. An option called "party with any". I checked it by default whenever I play since I don't really mind someone joining me when I have an open party (if I have a problem with them, that's what the kick is for ^-^).
But considering you have the option to create an open party already...what does this do? O.O If my party is already open, why is this there? Or does it draw random people into my party that are in a similar instance? But that can't be because then they wouldn't be the party leader of their own instance anymore...so really what's that option for? Or does it stop random people from joining my party if its unchecked, but if that's the case, why bother calling my party open?
Just in case you missed it somehow in your own options, see it here:
http://wiki.spiralknights.com/File:UI-options-general.png
Party with Any is a language option. Your default language is chosen with a drop-down and you will only be grouped with players using the same default language, UNLESS you check the Party with Any option.
Theoretically, checking this option would find you party members more quickly, on average, at the risk of being unable to communicate with some of them. As long as your default is the majority language, however, you shouldn't see much difference (edited to clarify, you shouldn't see much difference in time spent waiting for a party to fill).