If weather effects are included in a wargame, there are different things to consider:
- Determining the type of weather, and any changes in the weather during the wargaming day;
- The effects of the weather on movement, firing, visibility, etc.;
- For miniature wargames, how weather can be represented visually. But perhaps this is pushing things a bit too far?
Very much the same approach can be found in many miniature wargaming rulesets, in which the weather is rolled for - perhaps depending on season and location - and the resulting weather has an effect on movement, combat etc.
However, suppose we want to include changing weather during the wargaming day? Surely we want a continuous change, i.e. we do not want to have a bright and sunny day on turn 1, a snowstorm on day 2, to turn to cloudy and foggy the turn after.
In the classic book "Practical Wargaming" (1974), Charlie Wesencraft proposed an interesting mechanic to ensure we have this continuous change. The idea is to represent all weather conditions on a linear scale, and roll each turn for a step "up" or "down" on this weather gauge. The actual device could be simply a marker that is put on the weather gauge, or a little pin that is put in drilled holes, etc. The relevant 2 pages from the book are shown below, but the ideas was published a few years earlier in Wargamer's Newsletter, April 1971.
A particular useful variation might be to allow players to move the weather gauge up or down one step (instead of it being a random outcome), depending on some exceptional die roll during the game (e.g. rolling a 12 on a 2D6 during a command roll), much in the same way as we would allow a player to control the length of the game (see our blogpost about The Last Turn in the Game). Thus, a player might want to move the weather to conditions that favour him more on the battlefield for a given scenario or tactical situation.
Apart from a gradual shift each turn, one still has to determine the "starting weather" for the game. A useful tool for this is a "weather die", which has various weather symbols. Since the various outcomes can vary wildly (sun to snow), perhaps a second D6 can be used to indicate variations within the main weather rolled for.
Now, suppose we want the weather record for the 18th of June, 1815, near Waterloo. Of course, this pre-dates the actual archived and recorded weather measurements, but we could take the 18th of June in a year for which measurements are available, thus using a plausible weather pattern for our wargame.
Let's say we would like to have the weather at Waterloo, on the 18th of June. We use Brussels as a close enough location, so let's try to find the weather for June 18 in different years. (I used http://www.eurometeo.com/english/ for generating these reports, but there are a number of similar sites available).
This is the weather pattern for June 18, 2012 in Brussels:
And this is the weather pattern for June 18, 2016, again in Brussels:
So, use weather in your wargames as you see fit! And I am definitely interested in hearing about different weather systems that people have used in their own games ...