Dungeons & Dragons vs When Sky & Sea Were Not Named

Compare Dungeons & Dragons and When Sky & Sea Were Not Named side by side. See differences in complexity, dice, genre, cost, and more.

	Dungeons & Dragons	When Sky & Sea Were Not Named
Genre	Fantasy	Fantasy
Play Style	Tactical, Heroic, Combat-Heavy, Dungeon Crawl, Character Building, High-Fantasy, Grid-Based, Beginner-Friendly, Classic Fantasy, Lore-Heavy, Ascending AC	Tactical, Theater of the Mind, Resource Management, Faction Play, Lore-Heavy, Base-Building, Exploration
Core Mechanic	Roll d20 + modifier against a target DC (for ability checks and saving throws) or AC (for attacks). Meeting or exceeding the target succeeds. Advantage rolls 2d20 and takes the higher; disadvantage takes the lower, replacing most situational modifiers.	Each hero has four action dice, one for each action type (Attack, Brace, Compel, Maneuver), with the die size set from d4 to d12 by the relevant attributes. To act, roll the matching die and read it against two thresholds. Against an obstacle, the Guide sets a failure threshold and a struggle threshold. Against a foe, the target's attribute is the failure threshold and its defense is the struggle threshold. Beating the higher number is a Success, beating only the lower is a Struggle that costs something, and beating neither is a Failure. Attacks deal damage equal to the roll minus the target's Guard and Armor, so one roll settles both the hit and its severity.
Dice	d20	d4–d12
Complexity	Medium	High
Accessibility	Very High	Very High
Runnability	High	High
License	CC BY 4.0 (SRD); core books proprietary	All Rights Reserved
Cost	$$$	Free
Publisher	Wizards of the Coast	Purple People Games
Year	2024	2023
Best For	Groups who want heroic fantasy adventures with tactical grid combat, deep character customization, and access to more published adventures and supplements than any other RPG.	Groups settling in for a multi-session campaign who want combat built on resource trade-offs, spellcasters that each play differently, and a Guide comfortable improvising rulings. The island-hopping rescue-and-rebuild structure rewards tables that enjoy both tactical fights and settlement-scale stakes.
Highlights	Advantage/disadvantage system simplifies most situational modifiers to a single mechanic. Extensive class and subclass options across 12 base classes with 48 subclasses in the 2024 PHB. The largest third-party content ecosystem in tabletop RPGs. Free basic rules and starter sets lower the barrier to entry.	Each of the four defenses both resists incoming actions and doubles as the resource a hero spends to power abilities, so every turn weighs guarding against acting. A hero rolls a different die size for each of the four action types, so strengths and weaknesses live in which die they pick up rather than in numeric modifiers. Invoking an Ideal after a roll spends Spirit for an advantage die the Guide sizes to how dramatic the moment is, linking vivid roleplay to a mechanical boost.
Considerations	High-level play (tier 3-4) introduces significant spell interaction complexity and encounter balancing challenges for GMs. No official rules for non-fantasy genres. Three core books at $50 each represent a significant investment for the full rules.	The three spellcasting callings each run a separate resource economy, creating a real skill gap between players who take a magical calling and those who do not. The Shinarian origin locks Agility at 0, which bars the Wanderer calling and leaves those heroes unable to evade, outflank, or hide effectively. Sizing invoked Ideal dice, setting challenge thresholds, and reading the Dreamshape table all rest on Guide judgment rather than fixed numbers, which favors improvisational Guides over those who want firm procedures.