Greetings!
Mob attacks effective?: Sure! Imagine groups of flying archers, say groups of (10) 15th-20th lvl Fighters. Each group of ten remains invisible, flying, and firing barrages of arrows at
(1) Groups or individual wizards
(2) Obvious clerics and healers
(3) Front-line combat warriors, knights, fighters.
Depending on what else that you have going, such an ambush can be quite harrowing for the party. Toss in two groups of six or ten 18th level wizards that all agree to drop targeted fire-power on the group of wizards or clerics, and then have a phalanx of mounted knights or heavy infantry rushing in with halberds, and pretty soon, the party--even though they are of powerful, high level--they are milling about, struggling to survive and stay organized, while they attempt to fend off the hordes and quickly organize a plan of counter-attack. I would say that they have a system down, but it varies, because the enemies that they fight are different, and don't just do the same things. I'd say the group loses a henchman or two every other adventure. The party themselves, well, as you can see from the roster, there are significant gaps in power level. That is because of significant player-character and npc attrition losses through various adventures. It can, as you can imagine, get quite ferocious and bloody.
The actual incidence of blood and thunder combat must be kept, in my opinion, at a ferocious level, with mass confusion everywhere, and death at everyone's elbow. I admit that I don't use 6th level trolls. No, I use 16th level flying trolls who have bane arrows, and hide in ambush, and cooperate with a squad of giants as heavy infantry, with a good level of magic power, and they storm the group as they travel quickly. The essence in bringing terror to such a party is while the main wizard is being eaten alive, and is grappled, and can't cast spells, he then can't be protecting someone else. The enemy wizard or wizards can pound the clerics to mush, while additional enemy infantry swarms the party with arrows and hand-to-hand assaults. Even with creatures and characters of significantly lower level, the increased numbers, combined with cunning tactics, and liberal use of spoiling attacks timed precisely to keep the party off-balance, can make their life a living hell.
With dealing with a party of such power, as the Game Master, you cannot let them take their time to figure everything out nicely, and optimize every little spell. Hit them fast, hit them hard, and never let up the pressure. Make them make realistic decisions in a vacuum. There's fog, smoke, and screaming everywhere, in addition to flashes of magical Darkness, Light, as well as the constant screams for help, and the shouts of triumph, mixed with the screams of the dying, makes it very difficult for any sense of unit cohesion to prevail.
They don't, despite their often powerful spells and magic items--they don't know, feel, see, hear, everything, instantaneously, that is going on with everyone. They attempt to help the screaming paladin, while over there, in the darkness, evil dire tigers are shredding one of the clerics, and so on. Constant pressure, constant uncertainty, constant screaming and death.
Somehow, when the smoke and fog of battle clears, and they have buried the dead, and healed the wounded, the ones that have survived give thanks to the gods that they are alive, and they have survived another terrible onslaught by the forces of darkness. This of course doesn't necessarily take into account the occasional player-character or npc that is mentally disturbed, sometimes temporarily, and sometimes a few are driven utterly insane, gibbering and broken from the blood, savagery, and horror that they have endured. These characters must be grappled, and taken to a quiet monastery somewhere where they can hopefully live out their days achieving some semblance of peace and tranquility, for they have sacrificed those things so that others might experience them instead. They quietly retire in their enforced quest for peace. There have been three player-characters and 9 npc's that have entered a monastery in retirement.
Thus, such ferocious horde tactics must be used, so as to minimise the party's vast strengths, and bring them down to the level of blood and sweat. Doing so, consistently in my experience, keeps them quite humble, and keeps them firmly in mortal consciousness, for a savage and terrible death always awaits them should they make a mistake, or become arrogant.
Semper Fidelis,
SHARK
