Why Do We Roll Dice?

I think sometimes we lose sight of why we roll dice. What exactly is it about combat and other tasks that make them random? It is not simply that you have a 40% chance of success and therefore will hit four times out of ten. It is instead, chaos theory. There are too many variables involved in a system such as combat for a game to take them all into effect. Since neither players nor game masters know everything about the terrain, the weather, the manufacture of the arms and armor, the health of the two combatants, etc., it would be impossible to know if a breeze knocked an arrow off its course or if a sword found a weak spot in the armor. All these variables are represented by the dice. Random factors affect the success or failure of the attack. Why does this matter? I think it matters because it establishes a premise: The player does not know all the factors that are controlling his success or failure. The use of dice establishes this. So why do game masters insist on explaining to players all the modifiers that factor into their success or failure? I do it myself, sometimes. We’re trying to quickly do the math on an attack success and we walk through the modifiers. What I think is necessary is for the GM to sometimes say - your chance is X%. Why? I’m not going to tell you! Of course this upsets most players, especially the rules lawyers, but it’s meant to. Role-playing games are intended to have some mystery to them - that’s why you have a GM who knows all and players who don’t. We (as GMs) need to flaunt that a little more. Besides, if you can get them familiar with the idea that they will not always know the modifiers, then when you do need to keep something secret, you can slip it in far more easily. As a player, I use this idea as well. Let’s say I get lucky and hit three times in a row on a 40-50% chance of success. Role-playing, I will thank my deity, because clearly, that shouldn’t have happened, so it must have been divine intervention. Sometime other characters get upset about stuff like that. They are assuming that their characters fully understand not just physics, but the specific physics of that situation. The idea is ... well ... I’ll use the phrase foolish, because the words I want to use are not publishable. Yes, luck in and of itself is a factor, but how was it lucky? Did the attacker hit a pot hole and stumble? Is it really humid out and someone’s grip on their weapon was a little off, not enough to drop it, but enough to lessen the impact of the hit. I’m not suggesting you determine why every hit or miss occurred, just that you accept that sometimes factors that no one sees or senses still have an impact, and it’s OK for them to be secret.