Shapeshifting
Truth-telling is existential in its effect. If someone where to say "I am a Bear" and it was so, they would forever be a Bear. Seemings allow one to mask what they are, but it's a mere trick.
Since they lack a true identity as singular or multiple, things are without inherent nature.
When changing forms the creature maintains their current percentage of HP. Thus, if a 2HD man with 4/8HP becomes an 8HD Bear he will roll 8d6 then divide the sum in half to find his current HP value.
Creatures capable of true shapeshifting may change without limit or risk. Most are not so lucky. A being one wishes to change into must not just be known, but understood. 1 week of close observation and living near or among a creature grants sufficient knowledge and experience. Otherwise, after a close encounter it takes 1 month of constant studying, gathering stories, and imagination. The encounter is the key ingredient: it is not enough to see a Dragon, one must feel its breath on their neck.
Once transformed, there is a risk of losing all sense of self. Like death, this is beautiful but scary. After 1d6x10 minutes, rolled in secret by the referee, the shapeshifter must Save or be stuck in their new form for 1d6 hours. Once the hours are up they may Save again, and on a failure are stuck for 1d6 days. Once the days are up they may Save again, and on a failure are stuck for 1d6 weeks. Another failure, and they take this new form forever.
Pacts with certain beings, techniques protected by cults, and certain Wards may protect against this loss of self. The following Wards are generally applicable:
- For each person who knows your True Name add 1 to Save.
- If you have been trapped in that form for weeks and escaped then add 4 to Save.
- If you are in your homeland and know the ridges of the hills add 4 to Save.
- Drinking the ash of burnt peonies mixed with the dust of Fox bones before transformation adds 4 to Save.
Some cults have mastered limited transformations. There are stories of a woodland tribe whose people freely change between wolf and man, though surely at some terrible cost.