Trait: Wood
Effects with the wood trait conjure or manipulate wood. Those that manipulate wood have no effect in an area without wood. Creatures with this trait consist primarily of wood or have a connection to magical wood, or even Elemental Planes of Wood. Should they exist.
Wood is also one of the most common crafting materials in most civilizations, and is a basis for many crafting materials. As such, they will have this trait as well.
Creatures with this trait are typically immune to and deal Acid ⚙️, and Poison ⚙️; but are extremely weak to Fire, by the surprise of a few.