What unexpected action or ability made your encounter easier/harder than expected?

Third Ed. Player wants to try DM for a change, and runs one combat. Pulls out stuff that would put dandwiki to shame...some unkillable suit of animated armor that spawn dozens of critters each turn, then sucks out their souls to power his Limit Break. Drops the entire party in a round.

Well, except for me.

We had just finished a chapter in the overall campaign, and I had exactly one day left before graduation. So I let my character of several years retire peacefully, and rolled up the most munchkinney one-shot I could just to tinker with the mechanics. OK'ed by the actual DM. Character didn't matter so much, since it was just a guide for the party to reach the start of the next chapter. May as well have fun.

Luckily I picked a Vow of Poverty Druid/Monk, PrC'ed into Shifter. So I could wildshape into virtually any form, whenever I wanted, and had ridiculous bonuses no matter which form I chose. Started out with something simple, but when a TPK was evident I began shifting into more and more OP forms until I was basically fighting him as a dragon. Had to tank an entire Gauntlet-style horde while the others tried not to die.

Luckily, he didn't see my sheet beforehand (not being the actual DM), and was expecting a fight against a lv.13 Barbarian. More custom homebrew stuff comes out, unannounced. Obvious eleventh-hour attempts to help save "his" character. Several bad rulings that made no sense, but protected his little power fantasy. Luckily I was the veteran at the table and (barely!) could hang in there through a combination of system mastery and skillful gameplay.

Finally he decides he has to run, reluctantly, and tries to do so. NOPE. I have a form that's too fast. He tries anyway. NOPE. Every trick he pulls out, I have a counter for.

So now there's a forest that suddenly sprung up, one that hadn't been there before. "Oh, by the way, there just so happens to be the perfect place for me to escape to right nearby."

NOPE.

After hours of a slugfest, King Kong vs. Godzilla while the others ran around trying to stabilize one another, he forgot my munchkinbuild was first and foremost a Druid. A class which can pass through natural obstacles without being slowed down.

Suddenly, said forest was now a petrified forest, hoping that would nullify my class ability. Doesn't matter...it's still natural. Still a forest. He counters that I'm a huge dragon. Doesn't matter...I'm also a Druid. The forest gets out of my way.

Completely out of options, he gives up as I scoop up his deathknight in my jaws, fly towards the sun, drop him for terminal velocity, then stop flying myself to give him a cosmic bellyflop from the upper stratosphere JUST TO MAKE SURE.

And the entire party was saved due to a second-level fluff ability that's usually little more than a ribbon.

/r/DnD Thread