In the manual indicates the spell can be casted in a previous turn, to avoid the WIL roll:
As I understand this means it has to be pre-casted out of the combat. Does it mean the caster can cast the spell and keeping “warm” while they is moving among the dungeon until a combat occurs and the spell can be executed in a combat round?
Using a full Turn to cast a spell is usually for things like opening a portal or becoming invisible when you are not in combat. Outside of combat, casters can take their sweet time to cast a spell, so they don't have to make a WIL roll. This spell will take effect directly after that Turn so casters can't cook up a spell beforehand to cast during combat. This rule is there for when a caster wants to cast a spell outside of combat.
Combat in DURF should be a bit scary and stressful, so casting a spell during a fight it is a little risky.
Thanks, I am starting to understand one of the main philosophies on DURF: “combat is danger” :)
