Gaming sessions are a biggie for any achievement hunters, and a popular site feature. They essentially offer a way for site members to team up to unlock multiplayer and co-op achievements, which can sometimes be tricky to get. For instance, if an older game no longer has so many players, and the servers are soon to be shut down but you haven't yet unlocked all of the achievements; instead of being forever left with that unfinished completion percentage, you can reach out to other site members and organise a session so that those last niggling achievements can be unlocked.
The best place to look for gaming sessions for the achievements you need is on the Gaming Sessions calendar.
This shows every gaming session set up for every game. There are a lot going on at any given time, but you can filter them in a number of ways. First off, they're colour-coded depending on the type of session – some are competitive, some are for boosting a specific achievement, and some are casual co-op. You can also choose to view a week or day instead of the entire month, and then filter it in a number of ways, such as limiting to only the games that you own, or that you have added to your boost list, and so on.
To create your own gaming session, go to the Create Gaming Session
page. You can also find this page under the Create Gaming Sessions link in the Gaming Sessions portion of the Gamer menu. Pick can pick which game you want, and then pick which achievements you are looking to unlock during the session.
You can make it so that only your friends can join, or so that you can manually approve anyone who applies to be in the session. We'd recommend putting some notes in the box too, so that people know what your plan for the session is.
Once you've completed a session, you can leave feedback for the other players in your group, which adds to their overall session feedback score on their TA profile. Be nice.