tactical discussion, countering balrogs

[Lindolirian]

The Balrog yelled, and fell forward, and the fire of his being was extinguished in the Fountain, and he perished, along with Ecthelion, who, steel laden, sank into the depths, and so perished the Lord of the Fountain, after fiery battle in cool waters.

Keeper: This quote from the Fall of Gondolin has always made me think of the Fountain as a deep well because I can't imagine a great Elf like Ecthelion drowning in two inches of water. It is clear that it was deep enough to quench the weaking embers of Gothmog and drown and armour laden (not to mention rather tall) Elf.
In all seriousness, the most tried and true way to kill a Balrog has been casting him from a great height, but that's not always and option. Ecthelion killed Gothmog by stabbing with the spike of his helm, which I find downright hilarious. Correct me if I'm wrong but the only other descriptions of Balrog deaths are Glorfindel's and Gandalf's which were both done in by a great fall. Gothmog is the only one who gives us evidence that Balrogs can be killed by a physical wound which implies that their spirits are more tied to their bodies than Sauron's. Just ask Luthien and Huan about that one.
So the trick is either to overwhelm them by numbers (Rog and his House), impale them (Ecthelion), or toss them off a mountain.

Now if each of these fail, I'd say just send in a MOAB