Re: Rules of thumb for the "challenge level" of bad guy creation?
things to watch for:
1) SPD
- if you have lots of lower lvl goblins, like dbl # of your PCs, make sure the goblins are slower than your PCs or they will get overwelmed quickly due to per attack numbers. i.e; 3 PCs @ SPD 4 vs 6 Goblins @ SPD 5 = PCs 12 hits per turn vs Goblins 30 hits per turn. For 3 "equals" then it should be the same as the PCs, maybe 1 faster & 1 slower. And a big "dragon" type might be equal or 1 faster.
2) total points spent on combat
- if your PCs spent 175 but only "really" spent 140-150 on combat related stuff, due to the fact some of their skills and powers have non-combat uses, if their foes spend the full 175 on combat, that can present a challenge. Same goes for the goblins as above. Maybe 90-100 points for them. Basically the PCs should be 1-shotting those types. the big "dragon" should be 175% to 225% what the PCs spent on combat, so 300 pts +/- 50
3) CVs
-for goblin swarms they should be lower, for 3 "equals" they sould be the same to just a tad lower, for the "dragon" type creature it should be same to slightly higher. This helps even the playing field.
Overall keep in mind that behind the screen your dice read however to tell the best story. If it appears that you made an attack too powerful then pull back, switch targets, "roll badly" to hit. Whatever.
The battle should be epic, but not a pushover. I don't believe in a TPK. Only the potential to have the party wake from what they tought was defeat to end up working for the Dragon. For a while