If you’re looking for the game legitimately:

The core of the game is the "Deck" system. Before a match begins, players build a customized deck of units. You aren't given every unit; you must choose a specialization. Do you want a highly mobile airborne deck? A heavily armored mechanized division? Or a marine-focused naval landing force?

But what is SteamUnlocked? Is it safe? What are the specific consequences of pirating Wargame: Red Dragon ? This article breaks down the risks, the missing features, and whether the "free" price tag is worth the actual cost.