[For other posts in this series, click here, here, and here.]
When I started this series of blog posts, I deliberately avoided talking about the most obvious reason for including random elements in a game. For a game to be a credible simulation of a situation, even if completely fictional (for example, elves and orcs playing jai alai), it needs randomness. For reasons that I don't fully fathom, this argument for randomness sometimes leads into very heated discussions, so I thought I'd first tackle the less controversial but no less important reasons for randomness in boardgames. But there's no avoiding the necessity of randomness in anything that resembles reality.
No human activity is immune from having Dame Fortune appear unexpectedly to ruin your plans. Some situations may introduce fewer random elements than others: for example, you'll face fewer problems crossing the street than traveling to Vladivostok.You might stumble crossing the street, which is unfortunate. Traveling to Vladivostok, you might lose your passport, bad weather might cancel your flight, a pickpocket might steal your wallet, and no end of other mishaps might occur, orders of magnitude more than might happen crossing the street.
Nowhere can you see the importance of randomness in simulations than in wargames. There is a lot of randomness in real-world combat, so it's hard to suspend disbelief when playing a completely deterministic wargame. Designers may choose to simulate different random elements, even when they are depicting the same historical event. If you play a Gettysburg wargame that users a chit pull system (for example, Across Five Aprils), you're not certain when a particular general will get his troops moving. Another Gettysburg game, such as Gettysburg: Badges of Courage, might give the surrogate Meade or Lee more control over when corps commanders order their troops to move or fight.
Every wargame designer imposes some upper limit on the amount of randomness in a game, and where to include it. Many designers are hesitant to include too many random elements in the command and control aspects of the game, even though the unpredictability of C3I is a major issue in real-world conflicts. After all, one of the most famous anecdotes about the battle of Gettysburg is Ewell's failure to take Cemetery Ridge, despite Lee's direct (but vague) order to do so. Whatever side you take on Ewell's hotly-debated decision, the issue boils down to one of C3I.
The importance of randomness in simulations goes beyond the narrative of a particular battle. (What if Ewell had advanced on Cemetery Hill? What if McClellan hadn't received a copy of Lee's Special Order 191, wrapped around a bundle of cigars?) Uncertainty shapes how military organizations structure themselves, and how they operate. If randomness is important for the narrative, it's also important for how you depict the major characters and their actions.
BUT PREPARE FOR THE UNEXPECTED
If you're not a military history buff, you might not understand why historians stress divisions over other levels of organization in accounts of WWII battles. In a book or documentary, you'll more likely hear about the Screaming Eagles of the 101st Airborne division, not the 2nd Brigade of the 101st. The uncertainties of command and control are a major reason for why divisions were the atomic unit of battle for the US army in World War II. Every army is a bureaucracy, with the same limitations on the amount of flexibility you can allow into the organization without introducing too much chaos.
Uncertainty shapes the way in which commanders make their plans. The more complex the plan, the more points at which it can break down. A chief defect of Yamamoto's plan for the invasion of Midway, for example, is his decision to break the fleet into four separate task forces. The probability that all four task forces arriving on station, as planned, was extremely low, leading many later commentators (including some Japanese admirals) to highlight Japanese overconfidence (or "victory disease"). Had Yamamoto not scattered his ships and planes in this fashion, the Japanese fleet would have been better deployed to provide mutual protection while simultaneously executing strikes against the US fleet and Midway island.
How does a wargame simulate the risks that complex plans introduce? Frankly, most of them don't. You rarely see the importance of planning in actual combat, since units always take orders, they never get lost, and they don't encounter other mishaps when moving from point A to B. Wargames that do include the planning element, such as Fields Of Fire and the Tactical Combat Series, stand out starkly from the hundreds of other wargames that omit this feature.
Designers have some justification for not introducing too much randomness into the most basic tasks in a wargame, such as moving units around the map. Many of their customers complain loudly when a game doesn't allow this kind of unrealistic control over the battlefield, so designers are just responding to their market. To keep the experience of playing a wargame credible, you need to keep some element of randomness somewhere -- if not in the C3I aspects of the game, then in the combat results mechanics, or the timing of unit activation, or something else.