A question for two friends playing custom made races. One is a Monstrous Humanoid physically similar to a Lamia but with a larger bust and a less ridiculously long snake tail, the other is a Fey of humanoid shape with wings. Both wear armor, the Monstrous Humanoid is combat-oriented with a bit of spellcasting, the Fey is mainly a spellcaster.
First, is there a general rule about a Monstrous Humanoid or Fey being considered Humanoid or not to determine the price of armors, or is it solved on a case-by-case basis ? And how would it apply in my particular case ?
Second, do spells and other magical effects affecting only Humanoids work on Monstrous Humanoids or Feys ?