What's the formula for determining powerful charge damage? I have looked at the minotaur and the triceratops monsters and they each seem to have different ways for calculating the damage. Is this unique to each monster or is there some method to the madness?
Thanks,
Illius
Technically, it's unique to the monster. The method is left to the designer.
However, in the cases you've listed, the formula appears to be "roll the monster's gore dice twice, then add 1.5 times the creature's Strength modifier".
Examples:
Minotaur (19 Strength = +4 Str modifier)
Gore: 1d6+4 (note that the stat block uses it as a secondary attack, so it only gets +2).
Powerful charge: 2d6+6 (1d6 twice, add 1.5 * +4).
Triceratops (26 Strength = +8 Str modifier)
Gore: 2d10+12 (this is the creature's only natural weapon, so it gets 1.5 times its Strength modifier)
Powerful charge: 4d10+16 (2d10 twice, add 1.5 * +8).
Edit: This formula held up for the megaloceros and the mythic ettin as well. (Note that the mythic ettin uses a flail instead of a gore.)