Spell Slots
Spellcasters have a pool of spell slots by level. Casting a spell of 1st level or higher expends one slot of that spell's level or higher; cantrips cost nothing and can be cast at will. A long rest restores all expended slots (with a few class exceptions).
Casting Time, Range, Duration
- Casting time
- Most spells take 1 action; some take a bonus action, a reaction, or minutes. Longer castings require concentration throughout.
- Range
- Measured from you in feet; 'self' and 'touch' are common special cases.
- Duration
- Instantaneous, or a timed duration — many powerful buffs require concentration, up to the listed time.
Components
- Verbal (V)
- Chanting mystic words — impossible while gagged or in magical silence.
- Somatic (S)
- Forceful gestures — you need at least one free hand.
- Material (M)
- A component, replaceable by a component pouch or spellcasting focus — unless the spell lists a cost or says the component is consumed, in which case you need the real thing.
Concentration
You can concentrate on only one spell at a time — casting another concentration spell ends the first. You also lose concentration if you're incapacitated or killed, and when you take damage: make a Constitution saving throw, DC 10 or half the damage taken, whichever is higher. Environmental jolts (waves, earthquakes) can force saves too, at the DM's call.
Rituals and Save DCs
A spell with the ritual tag can be cast without a slot by adding 10 minutes to its casting time (if your class allows ritual casting). Your spell save DC is 8 + proficiency bonus + spellcasting ability modifier; your spell attack bonus is proficiency bonus + spellcasting ability modifier.