Larian Studios Forums Baldur's Gate III Baldur's Gate III - Help Tips & Tricks Saving Throw difficulty for Grease spell

Could anyone explain one SavingThrow issue to me.
When I cast Grease spell on enemies they should roll at least 12 to resist spell
But why 12, on what this threshold depends.

The DC (Difficulty Class - the number your target has to roll above) for your spells is largely determined by your stats and your class. High stats increase the DC, and your class determines which stat in particular needs to be high. Clerics and Rangers benefit from Wisdom, Wizards from Intellect, and Warlocks from Charisma.

Just as @fishworshipper (amazing name) said. Your spellcasting ability (intelligence, wisdom, charisma; depending on class) will determine how hard your spells hit and how hard they are to resist.

Example:
You have a wizard with 15 intelligence, which means you'll have a +2 to intelligence.
The D&D handbook explains the spell DC as followed: 8 + proficiency + int mod = 8 + 2 + 2 = 12. (proficiency is usually +2 at the start, and as a spellcaster, you're proficient with casting spells of course).
This means the opponent would have to make a dexterity saving throw (dexterity because it is trying to maintain balance on the greasy surface) against your 12. Meaning, if it rolls 12 or higher, It'll be unaffected by the grease. If it fails, it'll be knocked prone on the ground.

Great spell choice by the way. Grease can be a lot of fun and is a good crowd control spell. Don't forget that you're also susceptible to slipping on that slippery surface.


EDIT: I forgot to mention, if an enemy failes or succeeds against your grease spell; check the combat log (hidden with a tiny button to the bottom right of the screen). Hovering over some of the text might reveal which rolls happened in the background.

Thanks for answering guys
But I tried to cast this spell by Wizard with 17 or 18 Int and by Cleric with Magic Initiate feat and 10 INT (according to feat's discription Clerics also use INT for cast). Profiiciency +2.
DC was the same three times - 12.