Session Report-Back is a feature in which I jot down my after-action thoughts about my weekly D&D session for my Disciples of Dreth'dor campaign.

We last left off -- quite a while ago -- with the PCs having powered through a skill challenge that saw them climbing a giant staircase to the villain's lair while dodging obstacles thrown at them and falling stalactites from above. Having succeeded, they found themselves at the villain's main gate, greeted by guards.

The battlefield for this combat consisted of an outdoor and indoor area. First, the PCs had to fight their way into the lair before the gates closed, pushing through a vanguard of defenders before they'd be locked out for good. Next, they'd fight the remaining defenders in a chamber with a balcony at the far side, from which two ranged attackers could pepper them from afar while they cleaned up the remaining melee defenders.

This was the first time I introduced duergar in my campaign -- evil, black-skinned dwarves with psionic powers. A group of melee duergar were meant to keep the PCs from passing through the gate and possessed a power that seems, superficially, ridiculous: once bloodied, they grow to Large size. Running a serious, dark campaign, I decided to put a flavour twist on this power that went over quite well with my players.

As the players wounded the duergar, I describe the evil dwarves as beginning to tremble, to quake. Their veins throbbed, their muscles bulged, and stretch marks could be seen forming on their skin. Once bloodied, their growth to Large size became horrific, with skin tearing beneath expanding muscles and howls of agony mixing with crazed rage.

But the growth didn't stop there -- oh no. As the PCs continued to deal damage, the transformation continued, until that magic moment the first duergar dropped below 1 HP -- at which it exploded in a gruesome mess of giblets and blood that showered down on the PCs.

I place blood stains on my battle maps after particularly vicious kills, sized appropriate to the monster and savageness of the death. By the end of the battle, my players were satisfied with the path of huge bloodstains they'd left in their wake, leading through the gates and marking their progress.

The battle itself was down to the wire -- first, the gate nearly completely closed before they could enter, but through some clever manoeuvring and a bit of luck managed to position a duergar between the closing gate doors just as they bloodied him. His expansion to Large size flung the doors open and allowed the entire party to flood through.

As the PCs dispatched most of the defenders, they were drained of hit points and powers, left with a single foe left -- a dragonborn warrior who had been cockily observing the battle, seeming unimpressed. One by one, the dragonborn singlehandedly took down every PC until only the wizard was left, at which point a game of cat and mouse played out for a couple rounds. The wizard fled around the room, climbing onto the balcony and shooting magic missiles at the seemingly undefeatable dragonborn, knowing that with fewer than 10 hit points remaining, she could not take a single hit from him. Finally, with the dragonborn bearing down on her, she dealt the knockout blow that left his massive frame prone at her feet.

I love battles that are down to the wire. There's no greater tension than when the players truly don't know whether they will survive an encounter or not. The forward movement required across the battlefield added a great dynamic element to the battle, which, combined with the exploding duergar, will make this one of the campaign's most memorable fights. Unfortunately, you don't want to have a down-to-the-wire battle directly before your big boss fight...

The Good: Exploding duergar; a battle that necessitated forward battlefield movement; a down-to-the-wire struggle in which the PCs prevailed.

The Bad: The battle was too difficult; the PCs too weakened to be able to survive a boss fight. (Find out how I resolved that in the next Session Report-Back).

The Ugly: Only a couple players were able to stick around until the end of the session.