You do not have to buy CO if you already have retail Arma 2. You can combine those 2 together so they work as retail.
Its a little bit of work to do it but only needs to be done once and we have a sticky topic explaining how to combine the versions.
But, if you do not care about 4 dollars more sure buy the CO version and things will be at least a little more easy.
The Steam versions work equal with mods and addons like any other version. Only activating them when using mod folders (which you should always do) is a bit different than normal (retail, Sprocket versions).
- Steam sucks (thats my personal opinion).
- Steam seems to have issues now and than providing the latest official patches in time, like what happened with the recent 1.59 patch. I think it took Steam 2 more weeks to let its users download the patch which made it unable for many to join MP as most servers updated to 1.59 while Steam users were stuck at 1.57.
- With some patches you needed to re-download the entire game which is a few GB
while the patch itself only was 100 - 300 MB.
- Steam has a different way of modfolder activation and some people (probably since they dont read or dont read correct) do have issues for life trying to make it work. But if you read the provided info it should all be ok.
If you friend buys Arma 2 and later OA he will be able to run it in CO mode, thats always!! possible.
I also saw just now Steam has a "Steam Midweek madness" selling Arma 2 for 80% off and 40% off for OA and the DLC's. Might be a good time to just buy it all, also for your friend.
BTW, in case you do not mind to buy it without this extra deduction and like to support the developer directly and more
, you can always buy from Sprocket. Its easier to use (combine to get CO) and also the mod folder method is a bit easier. And patches are equal to the retail version so you are never left out.
For some Sprocket links to buy the games check our shop (yes, you will support us buying from Sprocket as well):
Sprocket is the channel from the developer selling the game directly to the gamers, meaning every sale goes directly to the developer which lets them earn more money which allows them to better support their game and make new games in the future
Ow, and welcome to Armaholic.
BTW, I renamed your topic title, a title should be descriptive, the fact you need help is obvious, with what is not