Fate Core vs METTLE Core

Compare Fate Core and METTLE Core side by side. See differences in complexity, dice, genre, cost, and more.

	Fate Core	METTLE Core
Genre	Universal	Universal, Modern
Play Style	Narrative, Rules-Light, Collaborative, Cinematic, Improvisation, Theater of the Mind, Low-Prep, Roleplay-Heavy, Drama, Freeform Magic, Open Source, Tag-Based, Social Combat	Pulp Action, Cinematic, Toolkit, Hackable, Open Source, Rules-Light, Theater of the Mind, Narrative, Classless, Fast-Paced, Fiction-First, Random Tables, GM-Friendly
Core Mechanic	Roll 4 Fudge dice + skill vs. difficulty. Spend/earn Fate points to invoke aspects.	Roll a pool of d6s equal to the Attribute being used. Dice showing 1, 2, or 3 are summed as the Score; dice showing 4, 5, or 6 are counted as Edge. The Check succeeds if Score meets or exceeds the Difficulty (Routine 1 to Nigh Impossible 15), and Edge measures how well it went. On a failure with Edge, the player may call for a Twist — accept a complication proposed by the rest of the table, then reroll the Edge dice for a second chance. Initiative passes from the acting character to the target of their Action, who becomes the next to act. Mettle (Motive + Nature) acts as a combined morale and damage track, and characters may Surge by spending Mettle for bonus dice on critical Checks.
Dice	4dF (Fudge dice)	d6 dice pool
Complexity	Low	Low
Accessibility	Very High	Very High
Runnability	Very High	High
License	CC BY 3.0	CC BY 4.0
Cost	Free (SRD)	$
Publisher	Evil Hat Productions	Planarian Games
Year	2013	2021
Best For	Narrative-focused groups who want to tell collaborative stories in any genre with minimal rules.	Groups who want fast pulp action-adventure in the vein of Indiana Jones, James Bond, or Tales of the Gold Monkey, with a hackable toolkit they can bend toward detective stories, wild-west gunfights, post-apocalyptic survival, or grounded science fiction.
Highlights	Genre-agnostic, encourages narrative play, free rules	Score-and-Edge dice pool reads two outcomes from the same roll: whether the action succeeds (Score meets Difficulty) and how well it went (count of 4–6 dice). Player-invoked Twists let a failed roll be reframed as a messy success in exchange for a fictional complication chosen by the rest of the table. Six-attribute character sheet (Calling, Culture, Frame, Motive, Nature, Poise) replaces classes and skills with player-written Descriptors that justify which Attribute applies to a given task. Initiative passes from the acting character to the target of their Action, eliminating turn-tracking and tying combat order to who is acting on whom.
Considerations	Aspect economy demands constant creative input which can exhaust players, character differentiation can blur with freeform aspects, requires system mastery from the GM to run smoothly	Toolkit framing means the book provides scaffolding (factions, NPC seeds, sample castaway adventure) rather than a fleshed-out setting — groups expecting a defined world will need to build or borrow one. Mettle does triple duty as morale, hit points, and a spendable resource for bonus dice, which can take a session to internalize. Twist resolution depends on the rest of the table proposing complications, which slows play if the group is hesitant to add fiction.