I do not understand this one.
It says play against someone who has this achievement,but how is the achievement obtained in the first place? I don't get it. Details,please.

I think they are just teasing us with that. :D

Or then it's an interesting experiment. Let's say that Team17 put it on one of their teams. They play against random opponent, who continues to spread that achievement forward by playing against other opponents, who also spread the achievement around the players. I'm sure that Team17 has some way to track how it's going and they are doing just that. Tracking its spreading. Why? Maybe just for fun or maybe they try to visualize just how random the random opponent mode is or how fast the achievement gets around and they can use the information for later purposes, whatever they are. You never know.

Basically it's possible that in said case the achievement could be stopped spreading after the first guy gets it, if he didn't want to share it with anybody. That is, if we assumed that Team17's team with that achievement played only one game, though how that guy could know for sure he was the only real player with that, let's not stick to that. After the first guy played, let's say, matches against 3 players, who each would play against 3 players and so on, it would get everyday harder and harder not to get the achievement at some point, if you just kept playing against other players. Remember Captain Tripps!

But yeah, like always with me, this is also only guess work, but theorizing things like this is always fun. :D

now I really want to get to the bottom of this.

yes,I guessed for a sec that they could be trolling,but it's more likely it's this thing you mentioned-one of the staff's teams(or all) are with this achievement and they will slowly spread it.

Sipuncula is spot on! Exactly that, when you play someone who's got the achievement you will automatically be awarded it! So if you get it, everyone you play afterwards will be awarded the achievement.

Where is it? At the moment it's locked away in a cage, under the stairs, in a darkened room guarded by a jaguar covered in landmines at T17 towers. It will only be released when the time is right and one of the lucky development team will be the first people to be infected with it, upon which they'll be forced to play a random opponent. After that...who knows what will happen!

Who will be the first infected?? Will it be Lead Programmer Darren with his Teesside twang? Or perhaps QA Adam (affectionately known as Qadam, not to be confused with Artist "Unofficial" Adam) with his perfect hair? (For those who are wondering, artist Adam has rubbish hair) Maybe it'll be new boy Gareth, the baking Web Developer? Perhaps it'll be the creator of the achievement, pie-man Simon? (Disclaimer - He doesn't really like pies that much. He likes chicken. He likes chicken so much he once ate 5 whole chickens for lunch and still had space for coleslaw). Or will the boss man, Senior Producer James, keep it for himself in his greedy little hands? It probably won't be me as I've just called the boss greedy...

WHO KNOWS WHO WILL UNLEASH THE ACHIEVEMENT?!

I lol'd :D

^ Me too. :D

And if it is that both opponents have more than 28 worms reinforcements and only one won?

Marco, it has nothing to do with reinforcements. You simply have to play an opponent who has the achievement already. We haven't released it yet though, so stay tuned to this wall to find out when it's out there! :)

This displeases me greatly.