I want to jump in here to clarify some things. This is a copy of a post I made a while back with some updates and clarifications:
REGARDING DRM
1 - There are two versions of Torchlight II - Runic and Steam.
RUNIC VERSION: If you buy from us directly, Perfect World, or the Daedalic retail box in Germany, you will get a Runic Key and everything will work the same for all of them. The game is "unlockable", meaning until you enter the key it functions in "demo" mode. Once you have activated, you are done in regards to DRM!
STEAM VERSION: If you buy from a partner that sells a Steam key (Gamefly/Direct2Drive, Gamestop, GamersGate) you will get a Steam Key that you put into your Steam client to unlock the game on Steam. Buying direct from Steam does not give you a key, it just links it to your account! Once you have the game on Steam, you are done in regards to DRM!
2 - The Runic version is an "unlockable" demo like Torchlight 1. This means you can download, install and play without ever purchasing a key, the game just has some restrictions. We have not stated exactly what these are yet, but for example you cannot play Internet Multiplayer (you need a Runic Account linked to a key for that) and there will be a content lock in place to prevent you from playing the entire game (like with the Steam Torchlight 1 demo ending on floor 5). If you like it, you can click "buy now" from the launcher and get a key, put it in and never get bothered again. No re-downloading. No re-installing. Just unlock and get back to the loot.
3 - With the Torchlight II Runic version the DRM will be the same as we had on Torchlight 1 - that is, a key with a generous number of activations by default (ten, the same as we had for Torchlight 1).
4 - We have, to date, NEVER turned down a single request for additional activations on Torchlight. It is actually rare for someone to consume TEN activations over a multi year period. I think we have had maybe 2-3 dozen?
5 - If you ask us for activation increases - We have access to the activation logs - if we see you requesting large volumes of activations from different regions of the world and different computers within a short time, We will be concerned and will ask you about it. We will want to know what is going on in that kind of sketchy situation (which, you must admit, would be really rare unless you managed to be plane hopping around the world and re-installing the game on a new computer at every airport and hotel along the way - at which point we will ask why, the story alone would be worth hearing

).
6 - If you ask us for activation increases and we see you have activated a bunch from your same computer or IP address over a short period of time, we will know that. I want to stress this in a way only Dr. Seuss can:
We do not care if you install it on all the computers in your house. We do not care if you use your mouse. You can try to install on WINE. If it works, that's mighty fine! You can play it on your LAN, you can play it on the "can" (although that might be difficult). We will up your activations, Sam-I-Am.
7 - With our DRM you will only need to activate ONCE on a computer, it will never dial home again (normal caveats about re-activating after reformatting your computer apply). There are no rootkits. There are no custom driver bullshit. There is nothing that accesses or interferes with ANYTHING ELSE on your computer. PERIOD.
8 - As we have stated before. In the extremely unlikely event that something happens and we have to stop supporting our product. We WILL release a patch that will remove ANY activation requirements at all. I know some of you will see this as an empty promise and there is not really anything I can say that will convince you otherwise. I can only say that has been our statement from the beginning and will not change.
REGARDING MULTIPLAYER, THE INTERNET AND RUNIC ACCOUNTS
1 - Your Runic Account is what you will use to log into for INTERNET multiplayer. You can create your account here:
https://secure.runicgames.com
2 - LAN multiplayer has NO LOGINS or any other requirement. You just start a game and start playing.
3 - The RUNIC version of Torchlight II gave you a DRM key - To register your Runic Account to play Torchlight II Internet Multiplayer, all you need to do is sign in (or sign up) to
https://secure.runicgames.com and register your key. Once your key is linked to your account you can play Internet Multiplayer - this linking also provides a handy way to get your key back if you lose it later.
4 - The STEAM version of Torchlight II does not need a key! All you need to do is sign in (or sign up) to
https://secure.runicgames.com and link your Steam account. To do so, you will be taken to a STEAM page to authenticate (we do not store any Steam authentication information) and that will allow us to link your SteamID to your Runic Account. This will magically register Torchlight II if you own it on Steam (yes, you can do this now!).
5 - The Steam link process does not "auto-update" itself - If you do not own the game and you link it to your Runic Account, you can make your purchase on Steam later and then come back to your Runic account and tell it to check again.
6 - An added bonus for linking your Steam account (AND YES, YOU CAN LINK YOUR STEAM ACCOUNT EVEN IF YOU OWN THE RUNIC VERSION) is a neat little feature we will be enabling shortly - the ability to Import your Steam Friends!
- To import your Steam friends, your Steam profile must be set to public - this is due to the way the Steam grants/denies access to your friends list based on privacy.
- Importing your steam friends will most likely be a manual process at launch, but easily done from your Runic Account page.
- When you start the import process, you will be asked if you want to allow your Steam friends to also add you when they import. This setting is saved with your Runic Account and can be changed at any time when you import or by going to Manage My Account.
Hope this clears things up!