There's been quite a bit of talk over the past few weeks on several of the D&D blogs about monster optimization.  You'll find all sorts of tips on powers, stats, and levels which will give you numerous options for customizing your monsters.  The D&D Monster Builder makes it simple to increase levels and adjust powers ad naseum.  However, when the claw meets the pavement, things may not play out how you expected.  An eager new DM learned that lesson the hard way.

Picture if you will, an eager new DM wanting to challenge his group of level 4 players with an encounter that challenged their new strength.  Picture him slaving away at the Monster Builder tweaking here, adding levels there, all the while making sure the XP budget was spent.  Now picture a single encounter that drags on for 3 and a half hours with the players getting frustrated and bored and casting dirty looks at the poor sod behind the screen. 

OK, so it was bad.  Maybe not that bad, but it wasn't pretty and it was completely the eager new DM's fault.  He made made the monsters hard to hit and on top of that, had bottled the PC's up in a hall way.  Now the PC's have to share at least some of the blame here.  They had shunned the powers that had lower damage but allowed the tactical movement of enemies, instead opting for maximum damage output.  Sure, they could have bullrushed, but no one seemed willing to take the attack of opportunity for breaching the line of HobGoblins holding them in the hallway.  It became a battle of attrition and potion popping boredom.

The eager new DM made several critical mistakes with this encounter.  Firstly, he became too enamoured with making the monsters harder to hit.  High AC doesn't make a monster more dangerous, it just makes it more frustrating to engage.  Without appropriate scaling of the monters ability to land hits and do damage themselves, they essentially became just a door that had to be hacked away and not a dangerous force to be reckoned with.  Granted, the dice gods were definitely not smiling on anyone that night, but there was at least one round where no one hit anything!  Yes... painful it was.  Wait... was I just channeling Yoda?

What the eager new DM should have focused on was finding balance.  Instead of increasing AC for AC's sake, he should have reduced the monsters AC while upping their potential damage output.  The sense of danger in an encounter comes not so much from an inability to hit a creature as it does from how hard the creature hits you. Lowering the AC, and other defenses if necessary, and raising the damage output of your monsters accomplishes two goals.  First, it keeps combat moving quickly without it becomming bogged down in a slug fest.  Second, it makes the monsters seem dangerous in the short term perhaps prompting greater thought on tactical movement.

Alright, fine... I was the eager new DM in the story.  I admit it.  It's when I finally started to realize the above little gem that my next encounter did excatly what I wanted it to do.  It was over in a reasonable amount of time with the majority of the monsters dead and two in custody while leaving the players stunned at the hit points that had been ripped away from them and thanking me for the inclusion of an NPC healer.  It also left them reeling from the demise of Splug, the spunky comic relief.  The hobgoblin forces saw him as a traitor and proceeded to let him hold their arrows.... point first. 

The bottom line is that there is a lot of art to the customization and the optimization of monsters.  Seek the balance that lies between survivability and damage output.  Find the combination that generates the most fear in your characters coupled with the bloodlust to engage and destory your monsters sooner rather than later.  Yes, there is an art here. Now, go find your inner Sun Tzu.