The "Studied Essence" druid class move reads as follows:
When you spend time in contemplation of an animal spirit, you may add its species to those you can assume when shapeshifting.
What is required to trigger this move? Does the druid have to actually encounter and study an animal spirit, or is it sufficient to encounter a live animal and then contemplate the spirit afterward? What about a fossil?
This is one of those things that you have to find out by playing, and working it out organically between the player and the GM.
Because there is too much about the fictional ingredients of the move that DW does not care to pre-define for a given campaign, GM, or world.
Such questions are inherently placed by DW into the realm of play, and you have to play to find out the answers. Some of these might be answered fairly quickly during character creation conversations (which is part of play), or they might wait until some epic, revealing moment of discovery during the campaign.
You have to play to find out.
Animal spirits are separate things from the animals themselves, and inhabit a spirit world that, through meditation and secret rituals, may be entered by a druid.
We didn't learn this until halfway through the campaign, when the Druid made her first journey into the Spirit World to retrieve her lost Elephant Spirit and to confront the Silence And The Dark that was tainting it.
Animal spirits are neither many nor one, but some kind of fuzzy in-between. A Druid has individual animal spirits bound in fetishes she carries with her, but there is also a singular identity that all spirits of a certain animal have that make them that kind of animal spirit. E.g., there are many Elephant Spirits (and this one is bound to me), but they are all part of the Greater Elephant Spirit, which being part of gives them their Elephant-spirit-ness.
Part of this was learned during character creation (when we hashed out that the Druid's access to spirits was through the fetishes and the spirits bound to them). Part of this was sort of hinted at as we explored the nature of the Spirit World.
Due to the above, the Druid would have to personally interact with a given animal spirit to learn it, understand it, and enter into a partnership allowing it to be bound into a fetish. Just watching a bear and contemplating its “bear-ness” was insufficient in our game, the way it turned out.
As a consequence of all that too, it remained possible that animal spirits of extinct animals would still exist. But we never found out, so that remains unanswered for our game. Certainly, a fossil was insufficient to access an animal spirit — however, it would be a clue to go looking for it on a Spirit World journey, and would probably make an excellent fetish-home for any such spirit discovered and befriended.
As you can see, these details were very, very dependent on the particular game we played. The very next game we played wasn't bound by these ideas either, and could have had very different rules for how the Druid works with spirits (but we have no Druid in that game, so we haven't found out yet).
Because without that, the GM is taking away from the player of the Druid a large part of their authority to say how Druids work. And if the Druid player is trying to declare how these things work based on trying to read the tea leaves of rules-as-written for secret truths, they're not letting the GM do their job of running the world. Anything in DW that isn't nailed down already by the obvious meaning of the rules is (according to the rules!) something that must “Begin and end with the fiction.”
Figuring this stuff out must be a partnership between the Druid and the GM, a partnership that exists during the back-and-forth of actual play, while the Druid plays their Druid and the GM follows the Principles:
To follow these principles, 1) every game must be true to its own, unique fiction, 2) every game is a new chance for the GM to get new answers from whoever is playing the Druid, in order for 3) the GM to be a fan of the picture of “Druid-ness” the Druid's player is painting with their sheet choices and answers to the GM's questions.
Engage your Druid player with these ideas.
Create opportunities to learn about how Druids and animal spirits work. Set up a situation where you don't know what is going to happen or how the Druid or the spirits are going to work, and then find out by playing.
Using situations without a pre-determined outcome is the tool for GMs to answers questions about the world — throw a situation at the players, and find out what happens! It's the rule, after all.
Ask your GM questions about spirits. Go to places where spirits convene. Ask character in the world how spirits work. Befriend animals, and learn from them what they know. Make declarations about how spirits and animals work in a way that triggers a Spout Lore, and see what you roll and what the fallout of that is. Listen to the trees and hear their slow, ancient wisdom. Try to see the spirits of animals, either by mediating or contemplating a certain animal in its natural environment. Do things involving animals or spirits while in danger, under pressure, or when it puts something at risk, so that moves trigger and unexpected fiction develops from their outcomes. In short: Do Druid-y things!
While doing this, stuff will happen — because when you try many things that are hard or uncertain a move will sometimes trigger, and you either succeed outright (10+) or something unexpected will happen (9−) that will reveal more about the nature of the world, animals, or spirits than you knew before. Even bad, unpleasant outcomes are revealing, and then you can build on and work with that knowledge to answer some of these questions.
At some point, whether early in the campaign or late, you will learn things that directly answer the question “what do I have to do to trigger Studied Essence?” and you'll be able to do it.
