Multi-player, Wikia, Population, Quality and Forums
There are two sides to the TL2 community. The first is that of the players, which is very active through both Steam and the Runic Forums. The second is that of the developers, which are essentially MIA. Unfortunately, Runic hasn’t done a good job of communicating with their players, and has done an even worse job by creating a fairly useless multi-player portal by omitting a chat system, which would have made all the world of difference (and would have been easy to implement).
Multiplayer comes in two flavors: LAN and Internet. While there are no requirements to create a server and play with your friends via a LAN connection, in order to play on the Internet you must log in with a Runic account because you have to go through the Runic TL2 Lobby. The lobby is very basic and only allows a player to create or join a server. Unlike Diablo 2 there is no chat system (which would have made a huge difference in my opinion). Unfortunately, the Lobby also segregates available games based on the mods (which makes sense, but also greatly limits the available games one can join) and the NG iteration, so the end result is a lot of players sitting on empty game screens because others don’t have the same combination of mods and/or aren’t in the same NG iteration. Ultimately, the lobby is poorly designed and doesn’t bring players together. I have also heard of numerous problems with internet-based multi-player. While LAN play works well, I have occasionally seen it get out of synch, and if it can do that on your LAN, it’s definitely a bigger problem with higher latency. The good news about multi-player is all of the loot that drops is yours (no ninja looting!) and you can easily teleport to any player in the game with the click of a button.
The TL2 Wikia is a great source for nearly every bit of information a player would want to know about the game.
Thousands of people are still playing TL2 on a daily basis via Steam (which doesn’t take into consideration those playing outside of Steam) so the Population of players seems pretty solid for a game well over a year old, but as I mentioned above, it’s very difficult to find other people to play with because you must have the exact same mods and be in the same NG iteration.
The Quality of the community in the Seam and Runic forums is very good. Players are helpful, and the authors of the mods (such as Synergies) are very responsive and easy to communicate with. The modding community is what really has kept this game alive especially since the last patch from Runic was in April of 2013.