In Dungeons & Dragons, a check is any d20 roll made against a Difficulty Class to determine whether a character succeeds at a specific task. Checks sit at the center of resolution in the game, translating abstract actions into outcomes that respect probability, character capability, and risk. This guide explains the core types of checks, how to build and interpret them, and how DMs and players can use them consistently to keep play fair, predictable, and fun.
What Is a Check in D&D
A check in D&D is an ability check or a skill check that uses a twenty-sided die (d20) plus relevant modifiers to compare against a target number set by the Dungeon Master. The target number, Difficulty Class (DC), represents how hard the task is, with typical DCs ranging from 5 for very easy tasks to 30 or higher for nearly impossible challenges. Checks resolve actions that are uncertain but not automatic, providing a structured way to model climbing, persuading, sneaking, recalling knowledge, and countless other attempts. When used with advantage or disadvantage, or with variable DCs, checks model risk, preparation, and circumstance in a reliable and transparent way.
Ability Checks vs Skill Checks
Ability Checks
An ability check ties directly to one of the six core abilities: Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma. Examples include a Strength check to shove someone, a Dexterity check to balance on a ledge, or a Constitution check to resist poison. Ability checks often underpin skill checks, because each skill is linked to an ability; for instance, Acrobatics relies on Dexterity, while Insight leans on Wisdom. Ability checks are best when the task outcome hinges primarily on raw physical or mental traits rather than specialized training.
Skill Checks
Skill checks represent trained competence, tying a specific skill to an ability modifier and, in many editions, a associated tool proficiency. Common skills in D&D 5e include Athletics, Stealth, Investigation, Medicine, and Persuasion. A skill check can represent searching for traps, sneaking past guards, or negotiating with an NPC. In earlier editions of D&D, such as 3.5, the term skill check was more prominent; in 5e, the distinction between ability and skill checks is emphasized through the rules for each skill. Skills are cross-indexed with abilities via the skill table in the Player’s Handbook, ensuring that players and DMs can quickly determine which modifier applies when a check is called for.
Making a Basic Check
To resolve a check, the player describes an action, the DM assigns a DC, the player rolls a d20, adds relevant modifiers, and compares the total to the DC. If the total meets or exceeds the DC, the action succeeds; otherwise, it fails. Modifiers can include ability scores, proficiency (when proficient), bonuses from tools or class features, and situational adjustments. Advantage and disadvantage replace flat bonuses with a more nuanced mechanic, rolling two d20s and taking the higher or lower result, reflecting favorable or unfavorable conditions. This structure rewards preparation, high ability scores, and skill investment while keeping uncertainty present. DMs should choose DCs that reflect the task’s difficulty and the fiction, avoiding arbitrary numbers that erode player trust.
Contested Checks
Contested checks occur when two characters act against each other, such as an Athletics check versus an Athletics check to grapple or an Insight check versus a Deception check to detect lies. In opposed checks, the active participant’s d20 roll competes directly with the opponent’s result, often with no DC involved. This framework is common in combat and social conflict, providing a clear way to resolve who has the upper hand. Because contested outcomes are relative, they emphasize character build choices, tactics, and the DM’s freedom to interpret descriptions into mechanical results.
DC Calibration and Consistency
Choosing the right DC is a key editorial responsibility for the DM. A consistent framework, such as the DC guidelines in the Dungeon Master’s Guide, helps keep difficulty predictable across sessions. Simple tasks might be DC 10, moderate tasks DC 15, and challenging tasks DC 20, with extreme or legendary efforts climbing higher. For routine actions, such as opening an unlocked door, the DM might decide no check is needed at all. The goal is to calibrate DCs so that success feels earned but never hopeless, and so that advantage, proficiency, and high ability scores meaningfully improve outcomes over time.
When to Call for a Check
DMS should call for checks when the outcome is uncertain and meaningful to the story. Checks are appropriate when the result could reasonably succeed or fail, when character capability should matter, and when a d20 roll enhances tension without removing agency. Avoid overusing checks for trivial actions or purely narrative moments that do not depend on chance. Clear communication about intent, context, and stakes helps players choose the right skill and approach. When in doubt, DMs can rule first and ask for a check only if the outcome is genuinely unclear, preserving flow while still honoring character agency.
Checks in Different Editions
Different editions of D&D handle checks in distinct ways. In D&D 5e, the rules for ability checks and skill checks are streamlined, with each skill tied to a fixed ability and clear guidance in the Player’s Handbook. In D&D 3.5, skill checks were more granular, and checks could include multiple modifiers, making them more complex but also more expressive. Earlier editions, such as OD&D and AD&D, used percentile-style skill systems and checks framed through referee tables, whereas later editions moved toward bounded accuracy to keep numbers manageable. Regardless of edition, the underlying idea remains: a d20 plus modifiers versus a target number, interpreted in the context of fiction. When discussing checks in D&D, it is important to specify edition, because terminology, DC ranges, and rules nuances can vary significantly.
Advanced Considerations and Best Practices
As play evolves, DMs and players can refine how checks are used. Critical hits and fumbles add layers of risk and reward, especially on attack rolls and some checks. Narrative checks can blend mechanical resolution with storytelling, allowing partial success, complications, or information revelation even on failure. Tracking repeated checks, such as investigating the same location over time, supports continuity and can reveal patterns. DMs should document common DCs used in their campaign, communicate expectations about proficiency and tool use, and periodically review whether checks enhance or hinder pacing. Used thoughtfully, checks remain one of the most durable tools for translating player intent into outcomes that feel both random and fair.