How do I open Dat File?

People often talk about *XXXXXXX* in DAT file... i'm confused, how do i open it or view it or whatever? Is this against the Rules/EULA?

MODS: Please move if in wrong location

It can't be "opened," per se, as it's a compressed file that most z programs won't recognize, even the better ones like 7zip. Feel free to read the GW.dat article on GWW (http://wiki.guildwars.com/wiki/Gw.dat_file_format) but if you don't know what that article is saying, chances are you don't know enough to "do" anything with the file anyway.

I believe there is a program out there called "GW Unpacker" or something similar that will decompress it for you, but this will be a long process, as the file is ~2.5-4GB in size. I should also point out that this is a gross violation of the EULA, though it is unlikely you will be punished (or even detected) for it.

why do you need to open the gw.dat file? If you have a problem you are better of to use the "-image" command and replace it, not mess it up further.

thanks all, very helpful

Detectable, never. It is impossible for anet to know what you do on your own computer. The only way they would know is if you talked about it on the forums (like we are doing right now) yet there is still no physical detection proof, another would be to monitor sites offering a tool to crack the GW.DAT and whoever downloads it, again there is still no proof you cracked the DAT. And another would be to detect it through the DAT itself when you load GW and it connects to ArenaNet, but you would normally copy a dat over that would never be used in GW again (so you don't mess your game up experimenting with stuff.) Essentially the only way they would know is if you post screenshots of the dat being hacked open and info spilling out of it on your screen, they'd be a bit upset. Cracking a file on your computer with a program that doesn't connect to the internet in any way is never going to be detectable, not today, not tomorrow, not in a million years. Other than that they can't hack your computer and look for your doing it because hacking you is pretty much something that they would keep under wraps and if detected, would be illegal and would have lawsuit written all over it.

But with that said, Even with no way to crack it at this point, I'm still not trying anything until they actually touch on the subject and say either yes or no, though the answer from them (with a .DAT type subject) will always be a beat-round-the-bush answer like with texmod. Since they still can't do anything about texmod being a Direct X texture layer program that doesn't connect to an internet port and dosent even TOUCH gw or it's .dat in any way physically or virtually possible.