The Oil of Slipperiness states:
Alternatively, the oil can be poured on the ground as an action, where it covers a 10-foot square, duplicating the effect of the grease spell in that area for 8 hours.
The Grease spell states:
Slick grease covers the ground in a 10-foot square centered on a point within range and turns it into difficult terrain for the duration. When the grease appears, each creature standing in its area must succeed on a Dexterity saving throw or fall prone. A creature that enters the area or ends its turn there must also succeed on a Dexterity saving throw or fall prone.
What is the spell save DC of a Grease effect put in place by the Oil of Slipperiness?
Best Answer
DC 13, probably
Another means of producing grease would be by casting it from a scroll. Spell scrolls generally have their DC determined by their spell level, and grease is a 1st-level spell, which means a DC of 13.
Magical items in general have their DC determined by their rarity, and DC 13 is the most common value used for uncommon items.