UPDATE (12-06-10) - After looking at the monster stats from the official MM3 previews, it looks like the damage increase is even greater than announced. The difference seems to be about 50% more at Paragon Tier, and up to 66% at epic. I've provided a table with the data below.
Monster Manual 3 is coming out soon - and, in fact some stores already have it. Judging from the comments of the lucky owners of early copies, this is going to be an even better book than the previous two in the series. To begin with, there's the revised format for monster stat blocks (presented here and commented here, though both links are sadly for DDI subscribers only), which presents monster information in a much more clear way - this is quite a blessing for the DM, as it greatly reduces the chance of forgetting a crucial ability. But probably the most significant change is one that affects players and DMs alike: an overall increase in monster damage.
I can't give first hand information as I still don't have Monster Manual 3, so the details will have to wait for a future post. What we know, for know, is that damage from all monsters (except maybe those in heroic tier?) is going up by 30-40%, and the balance between monster roles will be shifting, with Brutes (typically seen as the weakest type of monsters) now making attacks at normal accuracy (rather than at a -2, compared to other roles).
"...we increased monster damage output by about 30-40%."
The source is as official as it gets: Greg Bilsland, D&D game editor and one of the authors of MM3, has commented the issue on an interview at Critical Hits, as well as his own blog. Here are some of the highlights:
"...most older monsters up until about level 10 are performing just fine. It’s only around paragon tier that the damage really needs some adjustments."
"We reexamined the various roles and ended up adjusting brute accuracy back to baseline"
Without having seen the changes in play, I think they made a good call. Our campaing is still finishing heroic tier, but we're already starting to feel a decrease in monster threat. And I recently posted an analysis showing that the time it takes for a monster to kill a PC more than doubles between level 1 and 30. The greater monster damage will be a change for the good, particularly if they make the increase proportional to level, that is, you add more damage percentage-wise at paragon and epic tier. And anything that makes brutes more balanced with other roles (and not downright unplayable against higher level parties) is very welcome.
Some Tentative Formulas.
A while ago, I worked out a few simple formulas to describe the average monster damage across levels. I thought it would be an interesting exercise to see how these might look like, for post-MM3 monsters. I have applied a linear increase to them, so that level 1 monsters deal the same damage, whereas level 30 ones get the full 40% boost, and we have the following:
Attack damage, normal attacks
A quick patch for old monsters
- Low: 6 + 0.6*Level
- Medium: 7.5 + 0.85*Level
- High: 8.5 + 1*Level
A quick patch for old monsters
Following the formulas above, we can patch a current monster to MM3 levels by adding a fixed amount of damage to its attacks. The following values can work:
Monster damage increase
- Low: 1/5 * Level
- Medium: 1/3 * Level
- High: 2/5 * Level
You should modify these accordingly if a monster's damage is split among multiple attacks (i.e. divide the bonus by the number of attacks), unless it's an elite or solo, in which case you should probably add the full bonus.
Update: Sampling actual monsters
Out of curiosity, I checked these numbers against the monsters from the official previews. Sample size is small (just 7), but the results are consistently higher than expected. The damage increase seems to be about 50% for paragon monster, and 65% for epics.