So I’m working on the Gygax 75 challenge by Ray Otis. In part 2, the surrounding area, you make an encounter table for the area. The table uses a 2d6 roll, and he advises putting the weaker encounters in the middle of the range, so they are more common.
That’s all well and good, but I have a trade road moving through my area. I was thinking I should have one table for the road and one table for off the road. But there would be some overlap between the two tables, and I was trying to think of a way to make one table. Then I remembered the dice mechanics of Silent Death (an old spaceship combat game), and came up with 3M tables. Although I would not be at all surprised if someone else came up with this idea previously and called it something else.