System Reference Document 5.2.1
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idEntiFyinG an onGoinG spEll
You can try to identify a non-instantaneous spell by 
its observable effects if its duration is ongoing. To 
identify it, you must take the Study action and suc -
ceed on a DC 15 Intelligence (Arcana) check.
spellcaster can substitute a Spellcasting Focus if the 
caster has a feature that allows that substitution. To 
use a Component Pouch, you must have a hand free 
to reach into it, and to use a Spellcasting Focus, you 
must hold it unless its description says otherwise 
(see “Equipment” for descriptions).
Duration
A spell’s duration is the length of time the spell per -
sists after it is cast. A duration typically takes one of 
the following forms:
Concentration.  A duration that requires Concen -
tration follows the Concentration rules (see “Rules 
Glossary”).
Instantaneous.  An instantaneous duration means 
the spell’s magic appears only for a moment and 
then disappears.
Time Span. A duration that provides a time span 
specifies how long the spell lasts in rounds, min -
utes, hours, or the like. For example, a Duration 
entry might say “1 minute,” meaning the spell 
ends after 1 minute has passed. While a time-span 
spell that you cast is ongoing, you can dismiss it 
(no action required) if you don’t have the Incapac -
itated condition.
Effects
The effects of a spell are detailed after its dura-
tion entry. Those details present exactly what the 
spell does, which ignores mundane physical laws; 
any outcomes beyond those effects are under the 
GM’s purview. Whatever the effects, they typically 
deal with targets, saving throws, attack rolls, or all 
three, each of which is detailed below.
Targets
A typical spell requires the caster to pick one or 
more targets to be affected by the spell’s magic. A 
spell’s description says whether the spell targets 
creatures, objects, or something else.
 A Clear Path to the Target. To target something 
with a spell, a caster must have a clear path to it, so 
it can’t be behind Total Cover.
 Targeting Yourself. If a spell targets a creature 
of your choice, you can choose yourself unless the 
creature must be Hostile or specifically a creature 
other than you.
 Areas of Effect. Some spells, such as Thunder -
wave, cover an area called an area of effect, which 
is defined in “Rules Glossary.” The area determines 
what the spell targets. The description of a spell 
specifies whether it has an area of effect, which is 
typically one of these shapes: Cone, Cube, Cylinder, 
Emanation, Line, or Sphere.
 Awareness of Being Targeted. Unless a spell has 
a perceptible effect, a creature doesn’t know it was 
targeted by the spell. An effect like lightning is ob -
vious, but a more subtle effect, such as an attempt 
to read thoughts, goes unnoticed unless a spell’s 
description says otherwise.
 Invalid Targets. If you cast a spell on someone 
or something that can’t be affected by it, nothing 
happens to that target, but if you used a spell slot to 
cast the spell, the slot is still expended.
 If the spell normally has no effect on a target that 
succeeds on a saving throw, the invalid target ap -
pears to have succeeded on its saving throw, even 
though it didn’t attempt one (giving no hint that the 
creature is an invalid target). Otherwise, you per -
ceive that the spell did nothing to the target.
Saving Throws
Many spells specify that a target makes a saving 
throw to avoid some or all of a spell’s effects. The 
spell specifies the ability that the target uses for 
the save and what happens on a success or failure. 
Here’s how to calculate the DC for your spells:
Spell save DC = 8 + your spellcasting ability modifier 
+ your Proficiency Bonus 
Attack Rolls
Some spells require the caster to make an attack 
roll to determine whether the spell hits a target. 
Here’s how to calculate the attack modifier for your 
spells:
Spell attack modifier = your spellcasting ability 
modifier + your Proficiency Bonus
Combining Spell Effects
The effects of different spells add together while 
their durations overlap. In contrast, the effects of 
the same spell cast multiple times don’t combine. 
Instead, the most potent effect—such as the high -
est bonus—from those castings applies while their 
durations overlap. The most recent effect applies if 
the castings are equally potent and their durations 
overlap. For example, if two Clerics cast Bless on 
the same target, that target gains the spell’s benefit 
only once; the target doesn’t receive two bonus dice. 
But if the durations of the spells overlap, the effect 
continues until the duration of the second Bless  
ends.