I have recently been using Martin England's Threat Generation System, published in Miniature Wargames 373, for WW2 solitaire gaming. I have previously really struggled to create satisfiying WW2 solo games, because it isn't a "troops on the table" period. The distortions caused by the "helicopter general" effect, although present in all battles in all periods, seem to create the greatest dissonace in WW2 games. To me, to feel like a WW2 game, surprise and concealment simply has to be in there and simply turning the tables and playing both sides won't work when these are key tactical concerns. The author, Martin England, seems to have felt something similar, bemoaning the fact that his solo miniature wargames couldn't compete with the tension of playing computer games in this period. Even his face-to-face games weren't comparable: one can use dummy units and suchlike, but even they give far too much information about enemy locations and intentions .He (unlike me!) managed to turn his dissatisfaction into a suitable system for overcoming these problems.
In essence, the system is simplicity itself:
First, create an order of battle for the enemy. Each enemy unit will have a card and an equal number of blank cards are added. These cards are shuffled and a third discarded. I have adapted this system so that the enemy may have 'core' units which are added to the pack after this, so if "intelligence" knows that a platoon of Tigers is spearheading the attack, then there will be at least one Tiger card. You get the idea. This was very useful for the recent Op Martlet mini-campaign as a "core" British platoon takes on a "core" German platoon through the campaign.
Then generate the "threat" by drawing one of these cards every time a unit moves. I adapted this to be one card every turn to give a slightly slower game. To my mind, choosing this is a good way of controlling how the scenarios will play out: defending against an all-out assault will probably require a card for every player action.
A direction is then generated for the threat by a weighted dice roll (i.e. there is much more chance that the enemy will appear to the front, but a significant chance that some enemy will annoyingly appear on the flank), then a distance and then an activity (moving/static/dug-in etc.). The author also generates a simple "character" for the commander of the enemy unit to help him decide between actions when in doubt. I must admit I didn't use this, preferring a simple odds-evens die roll to decide between options when doubt arose.
There is more detail in the article and I would throroughly recommend that any solo gamer wanting to play in periods after 1900 should purchase the magazine and at least have a look. Science Fiction gamers might also be able to use the system. And the system itself is singularly adaptable, by making changes in the ratio of real cards to "empty threats", the rate of drawing the cards, the variation in the distances that the threats are generates, the "activity" of the generated unit, and so on. I'd like to thank the author and publisher for presenting such a useful and adapatable system. Highly recommended for the solo gamer!
And some examples of the system in action on my blog here