I've installed the game, played a beginning of first tutorial with no trouble, and then, when I've scrolled the screen... BAM! Graphics are all messed up. I'll just attach the screenshot:
I've also noticed the game does this only on maps where water is present.

Wow, I played this game for years, since its first release, and I never had such bug.
My guess is your graphic card doesn't like the water effects in the game.
As for the solution... Depends on the model you have... Try update the drivers, or contact the GoG support.

have same prob on 190.62 gf9800gtx+, and downgrading is nothing I call a "solution", tried various settings through nHancer. Recent GOG games are becoming more and more DIY from my point of view :(

Sadly, I have to agree with you - I hope it'll get better eventually. I'd like to ask you thou to contact support and, if you find a solution to the problem, post it here. I don't know when I'll get to my computer and I'd really like to have the issue solved as soon as possible. ... Pretty please? :D

omg GOG the things I have to do to play your games argR#%$^... I waited for the 191.07 drivers update but no go....so I decrypted the game's files, removed the fukin water & compiled the damn thing back into game, not very cool but at last...it's playable.
Download here for everyone desperate enough (readme included):
http://cid-00478f5cfebda60f.skydrive.live.com/self.aspx/.Public/GOG.com%20stuff/Praetorians%20no%20water%20patch.rar
there's probably some much better way since game seem to be highly modifiable, maybe some texture replacement or graphic tweak, but I'm not doing it xD I'm happy enough as it is....

I appreciate the effort to make a work around which worked for me.
It just seems a little odd to play without the water visual for me.
If this is a Windows 7 problem, I guess I can't complain since the game doesn't say "windows 7" yet. But if it isn't, I'm disappointed this wasn't better screened before going into the catelog.

thank you for the patch, I also have a 9800GTX+ and the same problem.

Just to confirm I've seen this issue on my main PC with a nvidia 480 but on a laptop with integrated graphics its fine. (Same O/S and patch level)

I've updated the nvidia drivers on the main PC and the issue is still there. Wether this is fixed by nvidia or GOG i dont know....

Shame as i love this game - hope its fixed soon

(water removal patch didnt work for me)

Thanks for the fix. It's of course not great that the water is missing now but at least the game is playable. Thanks!

I had the same problem (in fact i noticed it at the same point depicted in the screenshot of the original user).
I dowloaded latest driver from NVIDIA (v 280.26, my graphics card is a GeForce GT 330M) and now the games works perfectly.

Hope this helps,
Angelo

Yeah, I already found that solution in another thread but my particular problem is that I'm currently using a Sony Vaio laptop for gaming and unfortunately this hardware does not allow using other drivers than those provided by Sony - and to make it worse Sony stopped updating the drivers for this particular model two years ago. I have not found any way to use other drivers on this system. But thanks anyway.

Are you sure? i've a sony vaio too (a VPCF11M1E) and i've updated drivers going directly to NVIDIA website (http://www.nvidia.com/Download/index.aspx?lang=en-us), selecting option 2 (Automatically find drivers for my NVIDIA products.) and installing driver downloaded and it worked like a charm (i've windows 7 64-bit as OS).

I tried it many times but all I get is this message:
"The manufacturer of this system requires that you download the driver for your GPU from their support site."

Btw: My model is a VGN-AW21S with Windows 7 x64 installed. I also tried finding inofficial drivers but unfortunately all of them have the same version number as the last official update. This sucks.

Here is the water fix: praetorians .me/files/mods/Praetorians-no-water-patch.rar
(There is a gap before .me cause the forum does not allow me to write full links,
delete the gap before .me for the link to work properly.)