black -- encounter chance
white -- party surprise chance
red -- monster surprise chance
I ignore the red and white dice if black comes up nothing.
For attrition in the wilderness, rather than rolling up a full encounter on a positive result from the black die, I look to the other dice:
The white die determines "attrition dice" inversely to the number rolled on the die, e.g. 1 is 6d6, 2 is 5d6, 3 is 4d6, 4 is 3d6, etc.
Instead of an extra chance to "ignore" the encounter as I originally wrote, the red die can be used to determine "concretely" just what happened, thus:
1 - animal encounter -- a bear, a pack of wolves, a rutting moose, a baboon troupe, etc.
2 - men encounter -- a group of hunters, some brigands, some local ruffians
3 - humanoid encounter -- a skirmish with orcs, goblins, ogres, etc. per what I've generally said
4 - fey/unusual encounter -- undead perhaps, or faerie trees/briars that grasp at characters, etc.
5-6 - non-creature encounter -- a freak storm, a patch of poison ivy, a nest of young ticks, etc.
These are vague, and I think necessarily. As I said above, abstractness is the reason for these rules of attrition--what I get out of them is focusing on the dungeon while retaining some of the danger of the wilderness and travel through it. Attrition is a quick way to move through the consequences of the wilderness than having to describe an entire encounter with a band of orcs transporting prisoners, etc.
And yet, having a sense of what concretely the characters have encountered allows the players to respond to it with their skills, spells, etc in somewhat of the way that they would if presented with a full encounter. The best example I have is that if the referee rolls an "animal" encounter of six attrition dice, and the party includes a druid who responds by casting the spell speak with animals, the referee could allow the druid to just talk to the animals and avoid the encounter altogether, OR allow that spellcasting to replace one (or so) of the "usual" means of eliminating attrition dice (including the otherwise invulnerable sixth die, perhaps!).
|Perhaps the party encounters "animals"--the referee declares them spiders|
... and the halfling of the party uses his halfling abilities to sneak around
distracting the spiders with anti-arachnid slurs like, "Hey, atter-cop!"
Maybe an "unusual encounter" is undead, and the cleric can turn undead to eliminate an attrition die; or perhaps a group of men can be charmed or slept by a magic user to eliminate dice ... etc.
And of course, if the players just blithely accept the dice that you put forth, break their items, and move on, it's no skin off the referee's back. I just felt a strong need to have a way to clearly allow more player agency in response to the "attrition".