No battle plan survives first contact with the enemy, and similarly, gamemaster plans often don't survive first contact with the players. In particular, any elaborate, well-planned encounter will either end far more quickly than anticipated, as in this case, or go on forever. In retrospect, I should have known it would have been too easy, but somehow, it didn't occur to me at the time.

This particular story comes from a short-lived Advanced Dungeons and Dragons campaign I was running years ago. The player characters were a female gray elf mage, a male dwarf warrior with extraordinary strength, and a halfling scout. They had left the city to find a NPC human male paladin that had helped them before because a new ally, a female ninja, had warned them that he was in danger. They succeeded in saving him, but in the process, they had fallen into some long hidden underground ruins. After one fight against an angry spirit still here in this place, they found some more of their enemies: a ninja from a rival clan with some warriors.

This ninja was more of a ninja/mage, which was meant to be something of a surprise. The planned encounter would have them facing the four fighters first, as she was across a reservoir preparing to battle them. After they were defeated and the party either swam across the reservoir or ran around, the enemy ninja would use one of her special abilities and walk through a nearby wall. Once that was done, the dwarf would be allowed to knock down a nearby door and catch up to her. Then, as they inflicted enough damage on her, she'd continue to retreat through walls into other rooms, with the last part of the fight involving her using invisibility and a spectral warrior to fight them. Naturally, it would never get that far.

The dwarf knocked down the nearby door after the ninja retreated through the wall, and the first part of the combat encounter began. It'd also be the last part due to some extraordinary luck and my overestimation of how long I could keep an enemy with only double-digit HP alive. The elf hit with her attack with her quarterstaff, doing near maximum damage. The halfling hit with a critical hit, but the roll wasn't great, so she did about her normal maximum. The allied ninja missed, but it would hardly matter. The dwarf, wielding two axes and getting an extra attack that round, hit on all three attacks and scored a critical on one of them. With his extraordinary strength, it almost wasn't necessary to roll the damage, but just in case. Alas, she was not to be saved, as his rolls were all mostly on the high end, and thus this great enemy was to be taken down in a single round of combat.

After the enemy ninja first passed through the wall and the dwarf knocked down the door, the elf wizard cast Hold Person on her, not allowing her to escape so easily again. The dwarf, who was wielding two axes and had an extra attack due to his level, hit twice and even with low damage rolls, the extraordinary strength bonus still gave him enough to deplete almost half of her HP. The scout and the allied ninja both hit for a fair amount of damage, leaving the ninja with a little over a third of HP left. In the next round, the elf mage hit the enemy ninja with an acid arrow, inflicting 2d4 points of damage each round for four rounds. The enemy ninja finally managed to save against the hold and she retreated through another wall. This time, it took the dwarf a couple of rounds to successfully break through the locked door, but it didn't matter. I had rolled high on the acid damage both times, and though the enemy ninja won initiative that round, she missed on her attack and was killed by the next round of acid damage.