So what are those guidelines?
Looking over the tables, I have pretty much the same conclusion that Daniel at Delta's Hot Spot had when he looked at the tables: monsters of a given level usually have the same number of hit dice, with higher monster levels having a range up to 1 to 4 hit dice above and beyond monster level, and with Level 6 as a catch-all for more powerful monsters. Here are the guidelines I came up with:
- base hit dice for a given monster level equals the monster level;
- lowest number of hit dice equals the base hit dice minus (monster level/5, drop fractions);
- highest number of hit dice equals base hit dice times a multiplier based on monster level:
- 1 to 2: x 1
- 3 to 4: x 1.5
- 5 to 6: x 2