Readers of Gaming with Chuck will no doubt realize that I prefer gaming in the World of Greyhawk primarily, but the Forgotten Realms secondarily, if for not other reason that that these settings are designed to support FRPG situations, and also because of their familiarity. I actually prefer to do a bit of world design on my own, but even published worlds leave a lot to be developed, so I can strike a happy medium as a DM by using a published world (Greyhawk, Harn, Forgotten Realms, etc), and then developing a lot of filler for the world on my own. My ideas, presented here, on the tactics of trolls fill this area.
Tactics of trolls. Trolls are amazing beings. Ignore the regeneration bit, that was covered in Week One. Other than that, Trolls are natural climbers of the most astonishing ability (I believe that they have, according to an early write up, an 80% chance to scale sheer walls, and even higher for craggy surfaces). They can exist for extremely long periods with very little material resource. They are vicious, unrelenting, and nearly fearless in combat. They can adapt to and apparently mutate to accommodate nearly any sort of environ that they can be encountered in. Trolls have the animalistic cunning and enough intelligence to craft the most devilish of ambushes and trap-situations.
Tactically speaking, a creature with these attributes is incredible. A group of trolls could set up some sort of bait, with a nearby ring of ambush trolls hiding in some environ-appropriate concealing terrain. This might involve trolls hiding down a well, clinging to a ceiling, hiding under or inside furniture or wagons. Trolls can attack from having spent time (l-o-n-g time, if necessary) inside furniture, from a pool of quicksand, from underwater, or clinging to some overhead, out of the way, out of site hiding spot. Given their cunning ability to set traps and ambush victims, this might lead to some sort of distraction or bait being used to ferret out a party of adventurers.
Perhaps a lesser allied group of warriors (goblins, orcs, etc). this will create a loud ruckus, usually, and this is what the troll is counting on. The noise will alert the nearby trolls, who in a near torpor-like state, have been lying in wait in the most unlikely of places. Lets take a typical dungeon scene. An open (30' by 50') balcony area, overlooking a cliff down to a great underground river. The river is occasionally traffic'd by drow trading barges, but they are far below, and out of mind for the typical adventurer. Guarding some heaps of treasure on the balcony are a group of orc warriors (a dozen level 3 warriors, lead by a single level 5 chieftain). These orcs are bribed to stay here by the local trolls, who reward the orcs with baubles taken from the drow barges below (which are also ambushed by the trolls, from underwater). The trolls know that the orcs are not strong enough to keep the loot, and that adventurers or even other subterranean races will be attracted to the loot, fight the orcs, make a large noise, attract the trolls, and become lunch. I suppose that anything in the human or demi-human culinary tradition must taste better to a troll than orcs, goblins, gnolls, or any of the other lesser humanoid races they ally with.
In our example scenario, the orcs are found out by adventurers, attacked on the balcony, fought to near extinction, and create a large ruckus in the process. Now, a group of trolls in ambush attack. Some scurry up the impossibly high cliffs, creep over the balcony guard-wall, and attack. Some drop from the stalactite encrusted ceiling above the balcony, and some leap up out of the pit of offal that the orc guards have created in the process of living here for some time. This is a half dozen trolls, dropped in among the ranks of adventurers, spreading out and attacking all of them. By the third round, if the adventurers have not been able to recover and concentrate their attacks, the trolls will (as a group) begin regenerating 18 hit points per round (3 per troll). This is more than usually a couple of adventurers will average per round, so that the trolls will last for some time and should take at least one or more adventurers with them.
This brings up another tactical consideration of trolls. Trolls in the natural have three attacks (with approximately something around +6 or more per attack). These attacks are 2 claws (d4+4 damage each), and a shredding bite (d8+4 damage). Even if the troll turns in one of the claws for a weapon (perhaps a d8 sword, turning the d4+4 to sword damage +4, along with whatever magical bonus the sword may have - in our example above, imagine a troll with a drow blade), it still has another claw attack and a bite attack. If it turns in both claw attacks for a two handed weapon attack (perhaps mimicing the great spiked club of Vaprak, the deity of Trolls and Ogres), it might have a single attack of 2d10+4 damage. But it still retains the bite. What this means is multiple attacks. Multiple chances for a critical hit. If the troll has filth induced poison or special damage, then multiple chances to confer this to the target player.
I prefer to think of the rarest of instances where a troll gets three critical hits in one round (claw/claw/bite) as a troll trifecta. That will certainly make even a mid-level fighter step back a round or two and cry for help from the cleric.
Speaking of which, if you aren't using the critical hits from Arms Law/Claw Law, but rather something more conventional like the Good Hits/Bad Misses system from dragon magazine, perhaps it is useful to think of the claws as slashing attacks, and the bite as a piercing attack. It makes the critical hits from Monsieur Troll that much more interesting.
Additional Tactical concerns for a troll encounter would be either the trolls reliance on some sort of magical or shamanistic aid (perhaps from a troll shaman or cleric of Vaprak, or perhaps from some magical baubles that the troll has acquired from previous raids or ambushes). The troll certainly requires little in the way of healing (perhaps a charm or rune to enhance the regeneration?), already has a decent enough attack factor, does decent damage, is quite mobile in most physical locales, and is nearly fearless. The only area where magic seems needed would be in rendering some additional elements to the attack types - maybe adding a flaming or acidic or electrical component to the troll's claw attacks? Perhaps making the bite poisonous? Maybe even injecting some parasite creature that leaches off the life force of the victim? All good. All useful.
The troll uses its innate abilities (hide, climb, exist in a secure place near infinitely) to perform a debilitating ambush. As a group, there are multiple attacks, from the trolls, coming to multiple targets in the groups. There is a chance for critical with every attack (which do considerable damage). Even if the trolls are defeated, this is a strong foe for the DM to use. Even with very little outside influence this becomes a challenging encounter. Add an interesting setting, some compelling plot elements, perhaps a meta-encounter, and something that will engage the players, threaten the characters, and amuse the DM ensues.
Thank you, Mr. Troll, for providing such a good time.