Like the particle/wave duality of light, this week’s rules adjustments come from the understanding (or lack thereof) of how 4e swarms can act as both a single creature, and a series of tiny creatures acting in concert. The issue began when the party attempted to explore a web-covered chapel to a dragon god, buried deep in the caverns of the kobold lair behind the waterfall in H1. Turns out I wasn’t the only one who thought the provided map indicated a more extensive cave system – our DM has set us on his first completely original series of encounters exploring those caverns. And with webs covering the ceiling, it’s no surprise that we were attacked by spiders and ettercaps and scorpions (oh, my!).
Ignoring the annoying fact that those creatures could just pop out of the sky without warning, drop 80 feet and attack before we could respond ($%^& arachnids!), we had the most trouble with the accompanying swarms of spiders… well… swarming us! Forced to retreat after three straight encounters in the temple chamber, we adjourned until our next session. In the meantime, we realized we had been running the swarm attacks incorrectly, and the DM tried to be more literal with the rules as written on our return engagement.
But he was soon embellishing those with a few… questionable judgments. The first occured when our eladrin warlock tried to curse the nearest enemy, which happened to be one of the swarms. Nope, not allowed according to the DM. But he didn’t then count the swarm as the nearest enemy, so the warlock was allowed to curse a different ‘nearest’ enemy. In the middle of battle we didn’t take time to ask why, or at least our warlock, who is a pretty easy going guy, didn’t. The same wasn’t true for our avenger, when he later tried to declare an Oath of Enmity on a swarm, and was similarly rebuffed by the DM. At that point we discovered he wouldn’t allow any class ‘add-on’ to work against the swarms. Not the curse, nor the oath, or even the paladin’s Divine Challenge – or any sort of marking. He explained he just couldn’t justify in his mind marking, or selecting a ‘group’ creature like a swarm. You could mark an individual creature in the swarm, but that would be essentially useless.
How this meshed with allowing any sort of martial attack, even at reduced efficacy, I don’t know. And it was pointed out that adding immunity to those powers as well as the normal resistances a swarm receives to the types of attacks those classes tended to use was a potentially powerful boost. It essentially keeps a defender from being… defender-y. And the strikers were kind of gimped without their normal bennies against the collective creature. Of course, as usual, there were some offsetting rulings. Such as that the swarm only threatening the actual square it was in. Although the aura 1 still caused problems for those beginning their turn adjacent to a swarm, being able to move past it without getting an Opportunity Attack made for a more mobile battle than it otherwise might have been, and gave most of us an easier time escaping from them. Except for the paladin, ironically enough, weighed down by her plate armor. More than once she found herself standing on three swarms. I’m not positive, but I think the DM may have missed the part where Aura of the same type don’t stack, but regardless, our defender actually managed to defend us by being the slowest in the group in this particular battle.
One final point. As I said, sometimes our DM does listen to our objections. So when we managed to take out the the reskinned spider-beholder (and it stopped HEALING everything creature we got close to taking out), the remaining swarms rushed towards the slayer to take revenge – right past my wizard. I took my first Opportunity Attack, and missed. The DM was moving all three remaining swarms at once to save time (since as many do, we run similar creatures at the same Initiative), so I prepared to try an attack on the other two as well. Denied! The swarms were moving as a group, so only one attack, I was told. I retorted asking if he had rolled only one attack for the three swarms when they occupied the paladin’s square. Of course not, so I was allowed to continue, missing once more, but hitting with my druidic Grasping Claws, slowing one swarm and leaving it in range to be attacked by my Thunderwave on the next round. Awesome!