There are both official and numerous unofficial fan-run message boards in various languages focusing on many topics. Some of the more popular are listed below.
Other sites with message boards and chatrooms are listed in my Links Directory. There are also forums devoted especially to the Level Editor. See my Tomb Raider Level Editor links.
Wiki sites are collaborative projects that invite users to create and edit their content. "Wiki" itself is an acronym for "what I know is...", as well as the Hawaiian word for "quick". The most popular wiki is probably Wikipedia, which has subsites in many languages and covers a staggering array of subjects.
Since 2012 I have led a team of Tomb Raider fans playing for Extra Life, a charity video gaming marathon to benefit Children's Miracle Network Hospitals. Together we've raised more than $30,000 so far. We've also had a blast playing our favorite games, livestreaming, and making new friends in the community.
Extra Life happens each year the first weekend in November. If you'd like to be a part of the Tomb Raider Community team, just send me an email and I will notify you when Extra Life sign-up begins. For details about Extra Life, please check out my Team Tomb Raider Community Extra Life FAQ and visit extra-life.org.