I'm happy that there is a section to ask about features so here is my question:

I play volleyball and I have a list of people that can potentially play but we are limited to 12 players. So, is there a survey that send mails to people and picks the first 12 that wants to play? By the way, the seniority is important, like if the last one on the list (I call him Z) wants to play and that he is the 12th player, if someone else that is higher on the list decides to play, he will take Z's place.

Thanks and have a good day / night!

Not sure if I got this right but if you want people to answer a question like "Do you want to play Volleyball on May 11th?" (Yes/No) and you want to limit the number of "Yes" to 12, have a look at quotas: www.limesurvey.org/manual/Quotas

LimeSurvey is a data collection tool. It sounds to me like you're looking for an event or scheduling tool.

Thanks for your replies Mazi and TPartner! That will help me!