There's an interesting discussion on the use of "fate cards" on the Camp Chase Gazette's forums. This practice has been bandied around for many years to give a more realistic "feel" to the represented unit and to the event in general. I'll throw in my two cents of opinion in the use of fate cards.
First off, I like the concept of "fate cards" - they seem to allow a reenactor to fit into the historical skin of an actual participant of the battle. Everyone I've talked to have also liked the concept for similar reasons. Personally, though I've had questions about their true usefulness on the field, used as I understand.
Except for those rare instances of prophetic intuition, soldiers obviously had no way of knowing whether or not they would meet their maker in a particular battle. In a reenacting sense, fate cards give reenactors a little bit of insight to an actual soldier who participated in the historical battle, as well as his ultimate fate. In short, it gives everyone prophetic intuition. Does this add or take away from the purpose of fate cards?
Most reenactors are asked not to devulge their fate, but they do anyway. In my opinion, that's only natural. To be realistic, you'll have guys who are on board with what the event is trying to achieve and others are not. That's the first big rub about using them - it requires a subject willing to keep hush about what happens to make them a device that places you in the period groove. The second rub quickly comes next - following the directions, which again depends on the motivation of the reenactors. In essense, for fate cards to be effective, you must find a lot of like-minded reenactors.
Even if you have a event with like-minded reenactors, then there are other hurdles. One poster on the CCG site said he was in a position where he felt he had to take a hit to make the result look realistic, but he found himself not doing so because the fate card had his "alter ego" coming out of the battle unharmed. This where you have to think quickly on your feet and compromise. Many times has a soldier cheated death by sheer luck. But cheating death doesn't necessarily come without a price. Soldiers have been knocked to the ground stunned, given themselves to instinct and dived at the last second, simply hesitated and hid, been knocked silly, or simply ran. Not the best options in the world, but realistic ones.
One thought that came to mind recently is the fact that most battle reenactments are imperfect affairs to begin with. The best we can hope for is a close approximation of the opposing forces' movements within the battle. If that is the case, then fate cards should be approximate too. Face it, luck is luck. In normal circumstances, the blast of grapeshot described above would have killed everything in its path. No real way of getting around it. So rather than play the luck card, simply succumb to the reality of the situation.
Fate cards should be looked at as tools to guide reenactors, but not absolutes, especially in the face of common sense.