Thursday, September 6, 2018

Random Encounters and Space Hulk's Blips

Blindsight got me thinking about Space Hulk, which got me thinking about the blips.  Space Hulk has a mechanic where the alien player conceals his forces and moves them as "blips" on the human player's radar until they come into line of sight of a human unit.  It's a nice way to handle information asymmetry and partially hidden movement.  I think something like it might solve one of the issues with random encounters as they are played.

The way a random encounter in the dungeon goes in D&D (certainly in my games, at least) is usually something like this:
  • Party is doing stuff
  • DM rolls d6, 6 for random encounter
  • DM generates wandering monsters
  • Surprise roll
  • Reaction roll
  • Initiative roll
  • Combat 
  • Return to exploration loop
What's missing here is tension.  The encounter happens, it is resolved, it probably doesn't really link to anything else in the dungeon because it was just generated.  Resource costs are applied and then life goes on; there is no qualitative change unless the random encounter was on the way out while the party was already resource-exhausted.  It's almost like Bad Trap Syndrome, but with a combat intead.

The other thing missing here is that a rule has been ignored - the random encounter distance rule, another roll between generation and surprise.  Nominally should be 2d6 * 10 feet in the dungeon, in ACKS at least.  That's a long way (in expectation).  That's outside torch radius on average (30' of bright light, 20 more feet of shadowy illumination).  It's also outside of average monster infravision radius (60').  If you, like me, tend to not have 70' hallways, generally that's going to be around multiple corners or through multiple doors.  This is not typically a "the monsters come around the corner or through the doorway, roll for surprise" situation.

The reason this rule is ignored is straightforward - tracking runtime-generated state outside of PC line of sight is a hassle.  If you're using a graphpaper map, there isn't a good way to track groups of monsters moving through the dungeon.  Digital tools could probably handle this better.

But if you're willing to pay the price to track these 'blips' outside of PC detection range, the atmospheric and gameplay benefits are, I suspect, significant.  They turn random encounters from "fire and forget" into lingering threat, things just outside your vision, eyes reflecting your torchlight.  Waiting in the dark for you to make a mistake, stalking you, looking for an opportunity to pounce (or maybe just to eat your dead).  A heavily-armored party might not even be able to close with and engage such groups due to speed differences.  I suspect these lingering random encounters might encourage the use of thieves in the shadowed zone (where they can quickly pin down or drive off such enemies; pickets) and other "lightweight" play.  Multiple random encounters might lead to multiple groups of uncommitted creatures - morlocks ahead, morlocks behind, nowhere to run.  Depending on the monsters and the ecology of the dungeon, multiple "open" random encounters might fight among themselves (presenting an opportunity to players) or join forces.  Players might detect them with listening or detect evil...  blips on the paladin-scanner.

These things in the dark become a source of tension, a source of potential energy for the dungeon.  The other shoe, ready to drop.

On reflection, this difference in use is reflected in the old naming - "wandering monster" instead of "random encounter".


  1. Ah, that's interesting.

    Perhaps, then, allow Hear Noise to act as the wrist-mounted blip-dar; bringing in sight and smell? as well as hearing, to enable that sort of play.

    Something I'd been fiddling with is a system for "zonal combat", somewhat combining the theater-of-the-mind play with the miniatures play...mainly because the group has access to a 3D printer now and there's a lot of great stuff available cheaply.

    I've chopped down the various ranges for movement, missiles, and spells into maybe 6-ish zones - given that only the first 3 might be applicable to regular senses, that might be a way to keep track of the 'blips' without necessarily having to pathfind off your dungeon map on the fly. Might even go so far as to print out "blank figures" to represent unknown foes on the zone chart...

    I'd momentarily been keeping track of that sort of thing using a metal sheet and those magnetic push-pins - going so far as to print out, on transparency sheets, a little lighted "torch radius" to center the party's pin on. It was alright.

  2. Augh, you have such cool toys koewn (not just the 3D printed minis, but the torch radius thing too)! I am a little envious d:

    Yeah zones would make sense. IIRC Mongoose Traveller's starship combat system did something like this, with a circular, radial "map" cut into pie slices by direction and range band by concentric circles. The PCs were always at the center and other ships moved between the range bands and directions (and you got different amounts of information on them based on range and sensors). I think the direction aspect is important (for, eg, monsters on all sides, or progress forward blocked, or such).


  3. Ah, don't be too jealous. He got the cheapest special at Microcenter one day. It's more a testament to the continued commercialization of what used to be actual magic.

    Well, I'm following in proper footsteps then, my prototype for the idea is a hex-shaped hex grid, and as such you can build out the ranges by adding zone pieces off any of the six sides as needed. I'm not quite yet sure how this is going to translate to the dungeon, but I think this blip-dar idea has some potential for how to manage it.

  4. I will definitely experiment with this idea. I think the experience of actually adventuring in a dark place will be reinforced and by the players examining the sounds and smells of the monsters they'll be all the more monstrous.