Saturday, March 9, 2024

Arneson’s version of Challenge Rating

One of the more fascinating bits of information to be gleaned from Tonisborg is a section which reveals Arneson’s methodology of stocking dungeons. For those of us who have used Moldvay as our go-to guide for creating dungeons, we might expect an Arneson dungeon to have monsters in about one third of all rooms. If you are exploring dungeon levels 3-6, this is exactly what you would find; however, only 1-in-6 rooms on dungeon levels 1 and 2 have monsters and half of the rooms on dungeon levels of 7+ are occupied.

Each room that has monsters is assigned what are called “Protection Points” — a randomly determined amount of hit points that are used to “buy” monsters with. As described in Tonisborg, the number of Protection Points are based on an average party size of 4 to 5 PCs. Unfortunately, I found the table provided to be a bit confusing, but was able to take the concept and the described math to provide a very simple metric for determining the number Arneson’s Protection Points:

(1d6+1)(Dungeon Level) per PC*

*This assumes that that HD are based on a d6. This die would shift depending upon what the standard HD is according to the edition used.

Thus, if I were stocking the second level of my dungeon, I would be rolling 2d6+2 Protection Points for each PC in the party. So, if my party had 3 PCs the total number of Protection Points would be 6d6+6.

Additionally, Arneson had a “one sixth principle of monster variation.” On top of the dice rolled above, an extra d6 is rolled. Should that d6 result in a ‘6,’ there is a 50/50 chance that the number of points are halved or doubled.

Thus, in the example above, an average roll would result in 27hp; this would be halved to 14 hp or doubled to 54 hp with a ‘6’ on the variation die.

I have yet to try this method at the table, but in principle it does several things: 

1) It clearly sets up the expected danger of each dungeon level while allowing for some encounters to be surprisingly easy or hard. 

2) It despenses with the need to roll for the number of monsters encountered or for hit points. Both are simply assigned based on the number of Protectin Points avaible. In a way, it frees up the Referee to more exactly tailor their dungeon.

For example, our room on the second level has 27 Protection Points. This can be a typical encounter of 2HD monsters like 3 gnolls with 9 hp each. Or, it could be a bit more ridiculous with 27 goblins with 1 hp each. Or it could be a bit more chellenging with a single 5HD creature like a griffin with 27 hp. 

3) It allows for a kind of short hand when designing/stocking a dungeon. I can simple indicate the number of protection points each occupied room has and assign these points to monsters on the fly depending on whim, need, or random roll. It gives me the freedom to adjust some of the difficulty of a room by increasing or decreasing the number of potential attacks. For example, if I wanted to buy gnolls with my 27 Protection Points and my party needed a bit more of a challenge, I can increase the number of gnolls to 9 with 3 hp each; however, the overall deadliness of nine gnolls is somewhat mitigated by the fact that each will die from average hit from a PC.

This is an idea that seems far more practical than Challenge Levels and their equivalants in the modern game. It will also be something I will have to experiment with to see how it actually plays. Nonetheless, fascinating stuff!



gwiz said...

I just find it bizarre that a dungeon can have a Griffin in one room, five rooms away 3 Gnolls, and 5 rooms from there 27 goblins. That's a pretty interesting environment.

FrDave said...

There tend to be two major schools of thought on what occupies a dungeon:
1) Gygaxian Naturalism is the most popular, where dungeons make sense from a rational/naturalistic POV. If a dungeon has goblins, the dungeon should have all the things one might find in a place where goblins live (latrine, dire wolf kennel, goblin baby nursery, etc.
2) The Mythic Underground is the other. The dungeon is a character unto itself. It actively works against the PCs, producing monsters, traps, and new passages to try and lure them to their deaths. The lower one goes into the dark, the more power the dungeon has — it gets more dangerous with more dangerous monsters, traps, etc.
Both types date back to the origins of the game and both types are fun to run and build. As I grow older, however, I am more interested in exploring the capabilities and nuances of the latter. It challenges our modern ways of thinking about the world and I like that as a more medieval thinker. While Arneson's Protection Point system can be used according to both schools, it opens up the possibilities of the Mythic Underground in a way I haven't seen before.