Phantasm Chasm is a 1st edition AD&D adventure released in Dungeon #14 back in November 1988. I bought a fair number of issues between 1988 and 1993 and have used quite a number of the adventures over the years since. (It’s also become easy to track down digital copies to fill the gaps in my collection.) Even now, I can go back and find something I haven’t run before that can easily be updated to 3.5 or Pathfinder.
This adventure and the next one (for a later blog post) are both set in mountainous terrain and involve bandits and ambushes – just the sort of gaming set-up I wanted. I devised some mini adventures to lead into the two main ones and thought the mostly single session parts would be a welcome change from the sprawling adventure my group has spent the last five years completing. (What happened to those days when we might play four times a week?) Off-topic: I’ve updated my 3.5 Campaign page to cover the recent D&D sessions we have played, including this one.
The introduction: The characters discover the body of a man at the edge of the road. Apparently a mountain hunter or trapper, he has been stripped on anything of value and an orcish sword is still stuck in the corpse. Tracks lead to four more human corpses and a dead orc. All weapons and other valuables have been taken. At least a dozen humanoids of medium size have moved around the bodies and headed into the hills.
The background: Two illusionists (6th and 8th level) have almost taken over a tribe of 30 bugbears and convinced them that attacking adventurers can be more profitable than waylaying travellers, merchants or attacking villages. They have raided a tribe of orcs and captured some mountain hunters – using them to set up fake ambush sites along the main trails and roads through a mountain pass. Within a box canyon, they have what appears to be a small orcish camp. If the bugbears placed to watch the trails sight anyone approaching, one of the illusionists flies over them (invisibly) to see if they are worthwhile targets. A dozen orcs sit or stand around a fire near some ramshackle huts, while the illusionists and bugbears use the huts, massmorph and invisibility 10’ radius to hide in ambush.
Alterations: Originally designed for a party of about 6th level, I wanted to convert it to 3.5 D&D and make it interesting for a 12th level party. I changed the NPC’s to a 8th Sorcerer and a 9th Wizard (Illusionist) and the standard Bugbear warriors to 1st Fighter/1st Rogues. The two bugbear leaders and chief got a few extra Fighter levels. A wand of invisibility and a couple of castings of Invisibility Sphere meant I had hidden bugbears that weren’t likely to be noticed before they attacked.
I wasn’t expecting the 28 bugbear warriors to be particularly challenging after their initial surprise attack. With only a +7 morningstar attack they were only going to hit most of the party with very good rolls, but 35 hit points meant they weren’t going to be knocked down by a single blow from a PC. Essentially the adventure starts out with a few surprises for the party, but you could say the ambushers learn they have “bitten off more than they could chew”. Both casters were meant to be more effective, with defensive magic like blur, mirror image and shield (plus stoneskin for the wizard) combined with offensive spells (blast of force, darkbolt, confusion, friend to foe, shadow binding, etc). [In the original, the casters had little more than chromatic orb, colour spray and hypnotic pattern.]

The sprawling canyon on table-top
In first and second edition D&D I doubt that many people thought about the scale of maps in the adventures they were using. For third edition, with miniatures playing a big part, the size of the canyon map in Dungeon came as a shock when I started to look at actually presenting it as a battle-map. It’s approx 140 feet across and 260 feet long. The final product (1” = 5 feet) is composed of 20 sheets of A4 paper – thankfully we were playing on a large table!
The D&D Session: Thankfully my players started off by doing exactly what I wanted of them – they investigated the bodies and followed the trail. They moved up to the trees at the edge of the canyon and made a few minor preparations. Their wizard (invisible and flying) looked into the canyon, noted the orcs and even looked at the huts – spoting figures inside them. The group decided they might be captives and so the wizard put a maximised fireball into the middle of the orcs, aiming to not to hit the huts. He was quite surprised when all the orcs were vaporised. (5 hp doesn’t go very far.) Most of the other players moved in and the bugbears in the huts came out. This is when the cleric realised how big the area was and found she couldn’t cast beneficial spells on the spread out party all at once. Then the invisible bugbears started to pop-up around the party members away from the central melee, flanking in most cases. The two enemy casters begin to throw spells, and unluckily (for me) one failed a save vs a disintegrate spell and was gone. The other, like most of the bugbears lasted a few rounds more.
In Summary: It was a fun session – more interesting than a straight out fight. The players had to think a bit more than normal, more movement (not a 5’ step to another opponent each round) and certainly not the situation they had expected. If I was to do it again, I go with one of two options: 1. Less bugbears with more fighter levels to give them a better chance of hitting, or 2. Use a different humanoid with more HD, like Harpies or Minotaurs.