Wait a minute, I think you're a little confused here. A VAC enabled game is constantly checking for forced memory modifications (via memory modifiers like Cheat Engine, trainers, or modified game files) WHILE CONNECTED TO A VAC SECURED SERVER, to find gamers cheating in an online multiplayer game. And once it detects a memory modification, this memory log is sent using the Steam client's reporter to that server. You can check this if you set your firewall to a "learning mode" so any data that is trying to be sent, the firewall will ask you first if you allow this. This will obviously happen if you're playing in an online game, or in a single player game with leaderboards or other type of data that's going to be compared with others players, and saved.

In theory, you should be safe if you play with your mods or cheats in VAC enabled games ONLY IN OFFLINE MODE WITHOUT INTERNET, or WHILE NOT CONNECTED TO A VAC SECURED SERVER. You can always improve the chance to be in the safer zone by not cheating or modifying that game, or blocking that game with your firewall so it doesn't accidentally sent data or connects to a VAC secured server with you not noticing.

Remember, the VAC system was created to scan the memory of the computer of gamers while they're connected to a server secured with VAC, and this is used mainly in online multiplayer games or in single player experiences that share data with others in real-time online (like in Dark Souls II with the online features enabled). But if you are not online or connected to a server, you should not worry. Because you are not cheating or trying to get an advantage above others players. You're alone and offiline. The only victim of cheating is yourself, for not trying to play better... (:P)

Look for yourself, there are plenty of good information in the Internet about how VAC works.

You can turn Steam into offline mode to make the game go offline, no need to mess around with the firewall.

I normally run Steam in offline mode, when I started Dark Souls 2, it immediately warned me that I'm playing in offline mode with no online features available.

You can do that yes. But then you lose access to other online features of Steam, such as Friends. Some people don't want to lose those features. For that matter, Achievements may not unlock correctly and game time won't always be tracked correctly either with Steam offline. For some, these too, are important.

Yes, I know how VAC works (well, only what they said about it). To play offline I created a rule on my firewall, but of course I used come mods also when I played online (nothing special, it was the Durante mod to downsample the game, hid hud etc), because I can't delete the mod, reinstall it etc.
If they stated that the game was VAC secured, I would never install a mod to risk a ban (I'm on Steam from seven years, I know how it works and my library is HUGE, it wouls be a stupid move risk something only to mod a game).

I hoper for the best, of course, but the fact is:

-initially they promoted the game using old screenshots (the old, and better,build), then they removed those, using proper PC screenshot
-they released the game without VAC, implementing it without say nothing. There is a massive fan community for the game. Excluding cheaters, modders can "break" the game to try out a new mode. Now, all those people risk a VAC ban only because they didn't say anything about VAC presence in the game. It's right to punish cheaters, but VAC is a software, and can't detect a "good" injector from a "bad" one, used to take advantages upon other player instead to clean the game (as SweetFX utility, even if this didn't trigger a ban until now).

Yea, and this is why I implemented a rule on my firewall. Playing offline would be can't consult a wiki when I am stuck, I can't gain achievements, I can't chat etc.

Also, here's a video I found on community hub, it might be interesting:

http://www.youtube.com/watch?feature=player_embedded&v=FG6fo34JOAk

And also a quote from Durante, about the mod I used, directly from Neogaf:


"Yes, you could be banned for using GeDoSaTo.

Personally, I consider that fairly unlikely though. GeDoSaTo makes no changes outside of its own dll, and most significantly it does not alter the game state in any way. I believe VAC is selective enough to know the difference.

But don't blame me if you do get banned - the possibility is not 0."

Okay, fair enough. I couldn't care less about achievements and don't care if steam tells me how much I played it.

Guess I'm more of a antisocial gamer (when it comes to ingame), haha.

Now the VAC is missing from the store page :\