I just started playing university and created a sorrority and fraternity on my campus. I noticed people can use the phone to join a greek house, or a member can ask them to pledge.

My question is, how does the process work? if you join a greek house, is there a "process" involved with the pledge, or do they just move in? same with if a member asks a person. Do they just accept and move in immediately as a member? How does it work?

This is from compsimgames.com

Joining a Greek House
A sim that is renting or lives in a dorm, can join a Greek House by using the 'Ask to Join Greek House' selection on the phone. Members living in the Greek House will come over. Your Sim will be required to gain a certain number of relationship points with each member.

There's two ways to get members.

1. A non-greek house sim calls the greek house and asks to pledge. Then 3 members will come over (in togas) and you have six hours to reach a relationship goal with all of them. I'm not sure if it varies, but in my game its usually +50.

2. Or a greek house member can ask someone to pledge. If the person accepts they become a pledge, and can sleep/ use the fridge etc. on the greek house lot. They don't nescessarily have to move in. But the best part with pledges is that members can influence them for free. For 14 hours; as in, 14 hours with the new pledge on the greek house lot. After that they area full fledged member.

In my game, when you call to pledge, it is either 3 or 4 members that come to your lot to 'rush' you. You have to gain points with each to become a member and there will be a pop up box in the top right hand corner showing you your progress.

Unlike what FurryPanda said, there is no 50 relationship to get in.... it is more like you need 25 points with one member, 10 points with another, 15 points with the 3rd and 4th. It is not as hard to get in. (Oh and those relationship points you need to get are daily points, not lifetime.) Good Luck!

You can gain daily points pretty fast with all of them by hanging out or playing kickybag. Otherwise, you need to watch for them going into the dorm rooms of any Secret society members you have. (You can track them down by going into buy mode. That lets you see inside a dorm room that is claimed by another student.)