Spellcasting in D&D 5e looks complicated, but it runs on one idea: spells cost spell slots, and slots come back when you rest. Once that clicks, the rest is details.
Cantrips are free
Cantrips are level 0 spells, like Fire Bolt or Sacred Flame. They never use a slot, so you can cast them every turn, all day. They also get stronger as your character levels up.
Spell slots are your fuel
Every spell of level 1 or higher uses a slot of that level or higher. A level 1 wizard has two 1st-level slots: two casts of Magic Missile, Shield or Sleep, in any mix, before a rest. As you level up you gain more slots and higher-level ones — a level 3 wizard has four 1st-level slots and two 2nd-level slots.
Full casters (bards, clerics, druids, sorcerers, wizards) get the most slots. Paladins and rangers get fewer, starting at level 2 (level 1 in the 2024 rules). Warlocks are different: a few slots that are all the same level and come back on a short rest.
Casting at a higher level
You can put a spell into a bigger slot to make it stronger. Cure Wounds in a 2nd-level slot heals more; Magic Missile in a 2nd-level slot fires an extra dart. Each spell’s description says what it gains, under “At Higher Levels”.
Save DC and spell attacks
- Spell save DC = 8 + your proficiency bonus + your spellcasting ability modifier. Enemies roll a saving throw against this number to resist.
- Spell attack bonus = your proficiency bonus + your spellcasting ability modifier. For spells like Fire Bolt, you roll a d20 and add this, just like a weapon attack.
- Spellcasting ability: Intelligence for wizards; Wisdom for clerics, druids and rangers; Charisma for bards, paladins, sorcerers and warlocks.
Concentration, rituals and bonus actions
- Concentration: some spells, like Bless, last only while you concentrate. You can concentrate on one spell at a time. When you take damage, make a Constitution save (DC 10 or half the damage, whichever is higher) or the spell ends.
- Rituals: spells tagged “ritual”, like Detect Magic, can be cast without a slot if you take 10 extra minutes and your class allows it.
- Bonus action spells: in the 2014 rules, if you cast a spell as a bonus action, the only other spell you can cast that turn is a cantrip that takes an action. The 2024 rules simplify this to one spell slot per turn.
Getting slots back
Most casters regain all spent slots on a long rest. Warlocks regain theirs on a short rest, and wizards can recover a few on a short rest once a day with Arcane Recovery. Our guide to short and long rests covers what else comes back.
Track it without paper
Roleplayer character sheets show your slots as tick boxes, refill them on a long rest with one click, and roll spell attacks for you. Look up any spell in the free spell list — filter by level and class.