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Cortex Prime vs ESSER

Compare Cortex Prime and ESSER side by side. See differences in complexity, dice, genre, cost, and more.

Cortex PrimeESSER
GenreUniversalUniversal
TagsNarrative, Modular, Collaborative, Toolkit, Roleplay-Heavy, Character-Driven, Tag-BasedRules-Light, Theater of the Mind, One-Shot Friendly, Short Sessions, Fast-Paced, Low-Prep, Freeform Magic, Cinematic, Classless, Roll to Cast
Core MechanicAssemble a dice pool from trait sets (attributes, skills, relationships, etc.) rated d4–d12. Roll the pool, keep the two highest for your total vs. opposition, then choose an Effect Die from the remainder to determine magnitude. Plot Points let players add dice, activate abilities, or alter the narrative. Every mechanical element is a swappable mod.Roll d20 + skill bonus + attribute bonus. A result of 1–9 fails with a complication, 10–14 succeeds at a cost, 15–19 fully succeeds, and 20+ succeeds with an epic effect.
Diced4–d12 dice poold20
ComplexityMediumVery Low
AccessibilityHighVery High
RunnabilityVery HighMedium
LicenseCortex Creator LicenseProprietary
Third-Party PublishingNot yet researchedNo verified route found
Summary only, not legal advice. Check current terms before publishing.
Cost$$Free
PublisherDire Wolf DigitalEspen Erlandsen
Year20202026
LanguagesEnglishEnglish
Best ForGMs who want to build a custom system from modular parts: homebrew designers, genre-mixers, and groups tired of forcing their stories into a pre-built framework.Groups seeking a two-hour, genre-flexible one-shot where the same d20 engine handles action and conversation.
HighlightsHighly modular: 18+ mods for core rules alone, clear writing with worked examples, Plot Point economy creates dynamic give-and-take, powered well-known licensed games (Marvel Heroic, Firefly, Leverage)The same d20 roll handles standard checks and direct contests, making transitions between scene types quick. Interface scales open-ended supernatural or technical effects by skill tier, letting one procedure cover magic and hacking. NPCs need a core bonus, Strikes, and an optional trait, so a GM can prepare threats with few statistics.
ConsiderationsThe game is not playable out of the box and requires significant GM assembly. There is a steep learning curve to understand which mods fit your game. Every roll involves choosing which dice to keep plus an Effect Die, which slows resolution.No default setting is provided, so groups must supply a world for their adventure. Gear grants fictional permission rather than numeric bonuses, limiting equipment-based builds. Strikes reset after each adventure, so the track does not preserve mechanical attrition between adventures.