Wondrous Wednesdays: Genius Loci and the Hexcrawl Encounter Roll

 I was reading the Alone in the Labyrinth blog post "Genius Loci — Linking Encounters, Hazards and Reaction Rolls" and it gave me a few ideas. The concept is that, during overland exploration, each "hex" (or a number of hexes defined by a geological feature) has a genius loci, an entity that is tied to it, that forms from the magical (or spiritual) energy of a place the same way that life forms from the matter. And that the actions of a party might cause such an entity to regard them favorably or disfavorably; the blog post suggests a reaction roll for the genius loci instead of an encounter roll.

Now, this concept sees a lot of use in some settings. In Glorantha, every dang tree, stream, and maybe boulder has its own resident god, or spirit, or essence, depending on what kind of magic it's associated with. Larger genius loci associated with a valley or mountain might receive a lot of worship, and develop detailed personas that allow them to grant boons to worshippers (either as miracles, or as actual priestly magics). The smart party in that game brings along trade goods that can be left as offerings along the way, for those places where you're going to make camp -- no need to upset the spirits of a place with which you are unfamiliar.

In D&D, I don't think I'd roll reaction for each hex of travel. I use 6-mile hexes, so that would be a lot of rolling. Instead, I think I'd define a "magical landscape," a separate map that plots out entities on a varying scale of significance. I also don't think most genius locorum will take any notice of a party unless they do something to draw attention to themselves magically. Maybe I'd define a basic "mood" of a genius loci: a scale from "Enraged" through "Indifferent" to "Pleased." Then, if the party does something to draw the entity's attention, I'll roll an encounter roll to see how it reacted. A result of "Immediate Attack" would move the entity's mood 2 steps toward the Enraged portion of the scale; a result of "Unfavorable" would move the entity's mood 1 step toward Enraged; and, a result of "Very Favorable" would move the entity's mood 1 step toward Pleased. Then, I'd define some effect for the moods. Maybe Enraged causes the DM to reroll "No Result" encounter results, and Pleased means extra foraging results. You could make different effects based on what kind of entity the genius loci is: a Faerie genius loci should have different effects than an Elemental genius loci, and so on.