Novaseline

Im buying this just to play dayz mod. Which requires Arma2, operation arrowhead, then private military company(for high res textures). But from what i see, Arma2 is free. So do I only need to buy operation arrowhead and private company?(since arma2 is free?) Then i find different bundles. Any with both in a bundle? Thx.

Ok, im glad I asked now. They sure did make it very confusing for new customers lol. So if i bought arrowhead, combined operations, and PMC. I would be able to play dayz in highest resolution? I just dont wanna buy something, that doesnt help me play dayz. Then if I only bought those expansions, would i still have some lower res due to arma2free?