>>6041962I forgot to reply to this. My initial idea was you'd guess Rubida must hold a light against her breastplate, facing the wall, so to reflect the cracks and fissures onto it and opening the passage. In this case, you would have to bloodlet to get through, operating a sacrifice. It would have resulted into a minor penalty to checks, something like a -1d6.
The idea of casting a ray of light through the missing head surprised me -- not just because it was mechanically fitting and clever, but because it was also lore-abiding!
So I decided to eschew any penalty whatsoever. During the next thread(s?) I may do similar things for creative and inspired write-ins... so get that nogging goin, anon.
