If the price seems low (e.g., "just a drop of blood"), the real cost is hidden.

According to traditional lore and literary tropes, there are two primary ways to strike a deal: Oral Pacts:

First, a crucial distinction. If you summon a (Lawful Evil), you are dealing with a bureaucratic nightmare. Devils respect contracts, hierarchies, and fine print. They won’t necessarily lie to you, but they will absolutely let you misinterpret a comma that costs you your soul.