Tuesday, February 15, 2011

Foraging and Farming Rules for Classic D&D

Housing is not the only thing that the Domain Game expeditions are hurriedly throwing their energy into, the all-important task of hustling enough food out of the land to survive and thrive is another central arena.

Below are some more domain-play rule guidelines for handling foraging and farming. The agriculture rules will undoubtedly gain a good deal more detail as I expand the list of available crops beyond the simple grains modeled below.

These guidelines like yesterday's construction rules are a work in progress. Feedback is appreciated. 

Hunting and Gathering
Hunting and gathering can be a short-term fix for the food problem. A full-time hunter/gatherer can maximally sustain 4-16 individuals (including himself). The rate varies according to the abundance of game and other wild foodstuffs in a hex—and the skill and technology of the hunter.

Things to keep in mind with this activity:
  1. That you can only sustain a relatively small group of individuals in a locale. Thirty individuals for each adjacent five-mile hex of the hunting grounds. (Thus if you had a base camp area that hex and available hunting grounds in the surrounding six hexes could sustain up to 210 people in that area).
  2. The maximum rates are adjusted by season and climatic events. Game and other forage will be difficult in winter in cold climes or scarcer in a dry season in a more tropical one.
  3. Hunting at the maximum rate is not sustainable over time. Over several months of this activity the area you will have chances of declining yields due to over-hunting.
  4. This being a fantasy rpg there is always a chance that your hunters will encounter creatures other than what they are hunting out in the field.
All farming is conducted on a square mile basis (640 acres). Each five-mile hex contains 21.65 square miles.

However, not all land in a hex is arable. The GM will determine the number of square miles that are tillable in each hex (medieval manors had about 20-40% of available land under cultivation).

An average harvest of the “Big Three” mixed grains (wheat, barley, and rye) will support—after re-devoting seed back into the land—the equivalent of 186 people for a year. The harvest can also be converted into 4,480 bushels or 9,672 food/weeks for game purposes.

A minimum of 40 laborers is necessary to have a decent harvest, 64 is optimum. Throwing on more workers will improve yields up to a point.

Roll d20
1 or less Disastrous 50%
2-3 Poor 70%
3-6 Below Average 80%
7-14 Average 100%
15-17 Good 120%
18-19 Excellent 150%
20 or more Miraculous 250%

Tech level
-8 Tech level 1
-2 Tech level 2
+1 Tech level 5
+2 Tech level 6
+3 Tech level 7

+1 for every two Druids 3-5th level assigned
+1 for each Druid over 5th level assigned
+1 for each Cleric over 5th level


  1. So, if I understand you correctly, on average 1 mile^2 of land can support 186 people with enough of the 3 base grains for a year.

    It is interesting to note that manors in the middle ages averaged 600 acres in size, or just about 1 square mile. This would imply that most manors and their associated villages' total population could support right around 180 people during an average year, with no excess.

    Also of note is the 2 field system, wherein one half of the field is cultivated for a year, while the other half is left fallow and used as pasture for the animals (which then grace the land with their manure).

    Perhaps each hex/region of your campaign world could also have a land fertility index which would increase or decrease the yield due to exceptionally rich or poor soil.

  2. @Alan
    Yep that's correct, 186 per square mile if you are planting the traditional grains. I had the number 180 per square mile or 3-4 acres per person bandied about and was skeptical. But I did the math based on an average of a 9 bushel/acre harvest with 2 bushels going back in as seed and came around full circle to 186!

    Now the consumption side is debated as much as crop yields. Many sources say peasants ate 12-24 bushels a year. I decided to go for the high end to even out consumption by persons of higher station (and their horses). A bit of an arbitrary smoothing over on my part.

    If you wanted to go to the other end of the scale you could say that the square mile supports double that amount at a bare subsistence level.

    I thought about how to deal with the two and three field systems with their fallow fields (and twice annual harvests for some crops) and ended up just going with a smaller average number for the harvest as a fudge (though I may really have to reduce it further to make it realistic).

    Hmmm...I like the idea of modelling soil fertility. I had thought about assigning levels of quality to the mundane resources of each hex.

    I think I also would like to introduce some guidelines for percentages of arable land indexed to terrain. Something like grasslands hexes are 50-90% arable (1d4+5) or the like.

  3. This is a very enjoyable follow, lots to encourage. If you dare go even further there's a post up at The Tao of D&D on nutrition.

  4. @Porky
    Another great post on that site.

    Second edition C&S has a number of rules (there is no such thing as rations) that break foods down by type, weight, and amount of sustenance. The scale is probably too granular for me even if I dig these rules.

  5. This is great. But what tech level are you referencing?

  6. I think that most such rules reference tech level 3 or 4 (Think medeival Europe).