By adding new damage types on a weapon, you can alter the way damage is rolled.  Currently supported types:

• "brutal" (or "perkins") - crit dice will be set to the max possible
• "exploding" - if you roll the max on any damage die, you get another die of that type
• "cascading" - if you roll the max on any damage die, you get another (smaller) die (e.g. d12 - d10 - d8 - d4 - none)
• "voracious" - if you roll a 1 on any damage die, it will reroll (once per die)

Note that exploding and cascading are mutually exclusive, but other types may be combined.

Voracious is applied first. So if  you have a weapon that does both voracious and cascading damage, and you roll a 1 which is rerolled as a 6 (or whatever the max is for that die), then you will get the extra die.

Brutal/Perkins is applied last. So if you have a weapon that does both exploding and brutal damage, and you roll a max crit die, you get the extra die,. But if the brutal/perkins effect changes the die, it won't explode (or cascade).

The Sorcerous Burst spell (which is like exploding, but limited by the spellcasting modifier) is automatically supported (no need to tweak the damage type).