Cantrips: Essential at-Will Spells Reference

Cantrips occupy a unique position in Dungeons & Dragons 5th Edition — they are the only spells a caster can use without spending a resource, making them the workhorse of every spellcasting session from level 1 to 20. This page covers what cantrips are, how they function mechanically, when to use them, and how to think about which ones belong on a character sheet. Whether a player is building a Wizard for the first time or a Dungeon Master trying to understand what a veteran Sorcerer is capable of, the details below apply directly at the table.

Definition and scope

A cantrip is a 0-level spell that requires no spell slot to cast. The caster simply knows it, and that knowledge never depletes. In 5th Edition rules (Player's Handbook, p. 201), cantrips are described as magic practiced so often that the caster has internalized the formula — capable of producing the effect as easily as drawing breath.

Every spellcasting class in 5th Edition has access to cantrips, but the number known varies significantly. A Sorcerer starts with 4 cantrips at 1st level and reaches a maximum of 6. A Cleric also begins with 3 cantrips but can choose from a much broader list weighted toward utility. Rangers, notably, did not originally receive cantrips in the core 2014 Player's Handbook — that asymmetry is one of the mechanical signatures that distinguishes the class. Understanding cantrips is inseparable from understanding spell slots and spellcasting more broadly, since cantrips fill the gaps that limited slot budgets leave behind.

Cantrips belong to the same spell schools and types as leveled spells — Evocation, Transmutation, Illusion, and so on — and obey the same targeting, range, and component rules.

How it works

Casting a cantrip follows the same basic action economy as any spell: the caster uses an action (or, in a few cases, a bonus action) on their turn, declares the cantrip and its target, and resolves the effect. No spell slot is expended. The cantrip can be cast again next turn, indefinitely.

The defining mechanical feature of offensive cantrips is damage scaling by character level, not spell slot level. According to the Player's Handbook (p. 201), most damage-dealing cantrips increase at character levels 5, 11, and 17. Fire Bolt, for example, deals 1d10 fire damage at levels 1–4, 2d10 at levels 5–10, 3d10 at levels 11–16, and 4d10 at levels 17–20. This scaling means cantrips grow alongside the character without any additional investment.

The attack resolution depends on the cantrip type:

  1. Spell attack cantrips — The caster rolls d20 + spellcasting ability modifier + proficiency bonus against the target's Armor Class. Examples: Fire Bolt, Ray of Frost, Eldritch Blast.
  2. Saving throw cantrips — The target rolls a saving throw against the caster's spell save DC (8 + proficiency bonus + spellcasting modifier). Examples: Thunderclap, Poison Spray, Toll the Dead.
  3. Utility cantrips — No attack or save; the effect simply occurs within stated rules. Examples: Prestidigitation, Mage Hand, Guidance, Light.

That third category — utility cantrips — is easy to undervalue at character creation and nearly impossible to overvalue at the table. Guidance alone, a Cleric and Druid cantrip that adds 1d4 to any ability check, has generated genuine table debate about whether it should be available for every mundane task.

Common scenarios

At a combat-heavy table, a Wizard with two offensive cantrips and two utility cantrips is making meaningful decisions every round when spell slots run low. The offensive cantrip becomes the default action when preserving higher-level slots for critical moments — a practical rhythm that plays out across nearly every session.

Outside combat, cantrips do significant work. Message allows whispered communication across 120 feet. Mending repairs a torn sail or a cracked lock. Minor Illusion creates a sound or image within 30 feet, which can function as a distraction, a warning, or the setup for a creative solution. A party approaching a guarded gate with a Wizard who has Minor Illusion available is in a meaningfully different position than one without it — and the difference costs nothing.

The Warlock's Eldritch Blast deserves specific mention because it is, by design, the backbone of the entire class's damage output. At 5th level, it deals 2d10 force damage; at 11th, 3d10; at 17th, 4d10. Invocations from Xanathar's Guide to Everything and the Player's Handbook (such as Agonizing Blast, which adds the Charisma modifier to each beam's damage) build directly on top of the cantrip, making it a platform rather than a fallback.

Decision boundaries

Choosing cantrips at character creation involves a real tradeoff between offense, utility, and niche coverage.

The core decision breaks down along two axes:

One boundary that catches new players off guard: concentration spells do not interfere with cantrip casting. A Druid maintaining Entangle via concentration can still cast Shillelagh on their weapon and swing with it using Wisdom, because cantrips with instantaneous effects resolve without requiring concentration. The concentration spells rules page covers when that distinction matters most.

A character built around cantrips — the "cantrip-focused" archetype — typically appears in Hexblade Warlocks, Evocation Wizards, and Light Clerics, where class features multiply cantrip damage or add rider effects. For players interested in where cantrips fit within the broader mechanical map, the full D&D reference index connects these rules to every related system.

References