"Is Memoir '44 a simulation or not?" This was the big question in the latest contest from The Dice Tower. I did not submit an answer because I had no interest in the prize: Memoir '44 - Eastern Front. But I think the topic is interesting enough that I will put in my 2gg here.
Ultimately, this question comes down to simple semantics. We can probably all agree that games span the spectrum from very realistic to very abstract. But where do we draw the line? We don't. The line is at a different place for each of us. In fact, for different game types, most of us are probably not even self-consistent.
For example, if someone loves horse racing, they may consider the most abstract game of this genre to be a simulation because it is very evocative to them, while a more realistic game about German politics is not.
The theme of a game does not necessarily make it realistic either. Since it was a war-themed game that prompted this discussion, I'll examine the spectrum of wargames.
First of all, I suppose I should define simulation for myself. A simulation is an attempt to model real-world cause and effect. This also applies to fictional realities (fantasy, sci-fi) insofar as we understand how those worlds function with respect to our own. When playing a simulation, you should find yourself thinking about what would happen or what should happen if I do this and not what the rules say might happen. For me, this is where I draw the line.
If you sit me down in front of what I consider to be a good simulation, I should be able to make reasonable decisions without even knowing the rules. For example, in a wargame I would never consider running a squad of 5 soldiers across 100 yards of open ground 20 yards from a known enemy machine gun. This would be insane. If the game rules gave the squad a reasonable chance to make it, then the realism of the game goes out the window, and hence the game is not a simulation for me.
But even more importantly, what is it that various games are trying to simulate? Obviously even the most highly-touted WWII simulations do not model every molecule, they do not model hits on different body parts of soldiers, and they do not necessarily model soldiers eating and sleeping. They restrict their focus to the parts they feel are interesting and relevant to the genre.
At one extreme are the squad-level games where you deal with individuals and squads. At the other end are the theater level games that deal with entire countries as a single "unit". Is this less of a simulation because it doesn't handle individuals? No. The game chooses to simulate a larger scale. The effects of all the smaller events are factored into play. But this does beg the question: If the chances of an Allied victory in WWII were, say, 47%, then wouldn't it be just as much of a simulation to roll percentage dice and say you just simulated all of WWII in a single shot? It might be realistic, but it would not be fun.
People are not likely to call a game a simulation unless there is a substantial amount of detail and/or complexity an the scale at which the game focuses. Choosing A or B, and trying to roll a 3 or 5 will not be satisfying enough. We want every little decision we make to affect the results. We want to have enough going on that we can surprise our opponent once in a while, and suffer bad luck on occasion, just like in reality.
The bottom line is that you need to draw your own line to separate simulations from the rest. Debates over semantics are pointless in themselves, but they sometimes allow us to solidfy our understanding of other gaming topics. This, in turn, allows us to better evaluate and describe games.