This interesting question was posed by the folks over at Slitherine: “Does Complexity Define Wargames?”
In a word: No.
For me, what defines wargaming (as opposed to strategy games, a broader category which includes everything from Starcraft to Clash of Clans) is instead fidelity to reality. Wargames pose real world tactical or strategic problems that require real world tactics to solve. The setting doesn’t even need to be historical – one could imagine a near future wargame featuring plausible technologies and tactics, but that’s neither here nor there.
What matters to a wargame is not complexity or difficulty, but whether the world makes sense and the combat feels real. For example, one of my favorite strategy games (and a client), Unity of Command, is mechanically extremely simple. You move units, they have an attack and armor value, and the factors that go into combat are easily understood. What drives the game and makes it compelling is its supply mechanics, which attempt to replicate the effects of units being pocketed and cut off from food, fuel, and ammo. What happens is these simple mechanics come together to produce a larger whole. When you take all factors in to account, it is much more effective to bypass and pocket strong enemy formations than to take them on – which is exactly how real life blitzkrieg worked. 2×2 didn’t need to simulate every halftrack and rifle in a formation to guide the player down the path – instead they set out broad mechanics that encouraged that sort of gameplay.
Let’s look at a counter-example. Gary Grigsby’s War in the Pacific is a unique game – it simulates every squad, plane, and ship in a battlefield spanning half of the globe. It is a triumph of historical detail and fidelity. I have had fun with it, but it is a deeply flawed game. That very complexity (combined with an obtuse interface) means that it becomes very slow and can be annoying to play. It will always have a place on my hard drive, but I can’t really bear to play it for more than a few days at a time. And even with all its accuracy and with every unit possible simulated in the game, it still isnt’ always realistic. There are so many “gamey,” unrealistic exploits that most multiplayer AARs contain a laundry list of ‘house rules.’
My point is this: realism does not necessarily require complexity and complexity doesn’t guarantee realism. So, if you define “wargaming” by realism, wargames do not have to be complex.