Do Spells Go Against AC in 5e? A Comprehensive Guide
Fast answer first. Then use the tabs or video for more detail.
- Watch the video explanation below for a faster overview.
- Game mechanics may change with updates or patches.
- Use this block to get the short answer without scrolling the whole page.
- Read the FAQ section if the article has one.
- Use the table of contents to jump straight to the detailed section you need.
- Watch the video first, then skim the article for specifics.
The short answer is: Yes, sometimes spells do go against Armor Class (AC) in Dungeons and Dragons 5th Edition (5e). However, it’s not as simple as every spell targeting AC. The mechanics of spellcasting in 5e are varied, and whether a spell targets AC or requires a saving throw depends entirely on the specific spell description. Let’s delve into the details to understand how spells interact with AC and how spellcasters navigate combat.
Spell Attacks vs. Saving Throws
Not all spells are created equal when it comes to their resolution. Generally, spells fall into two main categories: those that require the caster to make an attack roll, and those that force the target to make a saving throw.
Spells Requiring Attack Rolls
Spells that call for an attack roll work similarly to weapon attacks. When you cast such a spell, you roll a d20, add your spellcasting ability modifier (Intelligence for Wizards, Charisma for Sorcerers and Bards, Wisdom for Clerics and Druids) and your proficiency bonus. You then compare the total of this roll to the target’s Armor Class (AC). If your roll equals or exceeds the target’s AC, the spell hits! If it doesn’t, the spell misses and has no effect.
Examples of spells that require attack rolls include fire bolt, ray of frost, scorching ray, and eldritch blast. These are often spells that create beams or projectiles that need to be aimed accurately.
Spells Requiring Saving Throws
On the other hand, many spells do not involve attack rolls. Instead, they require the target of the spell to make a saving throw. In this case, the caster doesn’t roll a d20 at all; the target does. The spell specifies which ability score (Strength, Dexterity, Constitution, Intelligence, Wisdom, or Charisma) the target must use for the saving throw.
The target rolls a d20 and adds its relevant ability modifier. The caster sets a Difficulty Class (DC) for the spell, which is usually calculated as 8 + the caster’s proficiency bonus + the caster’s spellcasting ability modifier. If the target’s roll meets or exceeds the spell’s DC, the target succeeds in the saving throw, and the spell effect is often mitigated, sometimes resulting in half damage or the spell having no effect. Failure means the target succumbs to the spell’s full effect.
Examples of spells that require saving throws include fireball, lightning bolt, hold person, and sacred flame. These spells often create areas of effect or attempt to affect the target’s mind or body directly.
Why the Difference?
The difference between attack roll spells and saving throw spells boils down to the nature of the spell. Spells that require a direct, aimed attack often require an attack roll against AC. Those that involve manipulation of an element, a psychic assault, or a sudden burst of energy typically require a saving throw.
Spell Critical Hits and AC
Like weapon attacks, spells that involve attack rolls can also score critical hits. If you roll a natural 20 on your attack roll for a spell, you score a critical hit, dealing double the spell’s damage dice. It’s important to remember that critical hits only apply to the damage dice, and not to any flat damage bonuses. Spells that force saving throws don’t typically have critical hits; they either succeed or fail.
Understanding Spellcasting in Combat
Spells can be cast using an action, a bonus action, or a reaction, depending on the spell’s casting time. It’s important to note that casting a spell isn’t typically considered an “attack action,” except under very specific circumstances like the Bladesinger’s Extra Attack ability. Most Extra Attack features, which allow you to attack twice, apply specifically to the “Attack” action and not the “Cast a Spell” action.
Frequently Asked Questions (FAQs)
Here are some common questions about spell attacks and AC in 5e, expanding on the core concepts:
1. How do I calculate my spell attack bonus?
Your spell attack bonus is calculated as your spellcasting ability modifier + your proficiency bonus. For example, if you have a +3 Intelligence modifier and a +3 proficiency bonus, your spell attack bonus is +6.
2. What is considered a spell attack in D&D 5e?
A spell attack is a spell that requires you to make an attack roll against a target’s AC. This includes spells with ranged or melee attack rolls.
3. What’s the difference between an attack roll and a saving throw?
An attack roll is performed by the caster when the spell requires them to aim. A saving throw is performed by the target when the spell directly affects them, forcing them to resist the spell’s effects.
4. Do all spells target AC?
No, only spells that specify an attack roll target AC. Spells that require the target to make a saving throw do not target AC.
5. Can spells critically hit?
Yes, spells that require attack rolls can critically hit. A natural 20 on the attack roll doubles the damage dice of the spell.
6. Do spells get extra attack?
No, extra attack features do not allow you to cast extra spells. Extra Attack is tied to the “Attack” action, not the “Cast a Spell” action.
7. Does the caster roll a d20 for a saving throw?
No, the caster does not roll a d20 for a saving throw. The target makes the saving throw, rolling a d20 and adding their ability modifier. The caster calculates the spell’s DC (Difficulty Class) instead.
8. What does AC stand for?
AC stands for Armor Class. It represents the target’s difficulty to hit based on their armor, natural defenses, or other protective measures.
9. What is a good AC in 5e?
An AC of 10-12 is considered low, 13-15 is medium, 16-17 is solid, and 18+ is considered very good or great.
10. How is AC calculated?
Your AC is usually calculated as 10 + your Dexterity modifier if you’re not wearing armor. When wearing armor, use the AC provided by the armor type, and the amount of Dexterity modifier you can add depends on the type of armor you are using. Heavy armor does not include a dexterity modifier.
11. Is 20 a high AC?
Yes, an AC of 20 is very good and difficult for most enemies to hit, particularly at lower to mid levels.
12. What is the highest possible AC in 5e?
While most creatures have ACs around 10-25, it is possible to reach much higher ACs with specific builds, magic items, and spells, potentially exceeding AC 50.
13. Can I hold spells?
Yes, certain spells can be held, typically by using your action to cast the spell and then your concentration to hold it until the conditions you set are met.
14. Can I use my Reaction to cast a spell?
Yes, if the spell’s casting time is a Reaction. Only certain spells, like shield or counterspell, have a reaction casting time.
15. What happens if a spell misses?
If a spell that requires an attack roll misses, the spell has no effect. If a target succeeds on a saving throw, the spell may have a reduced effect or no effect, as defined in the spell’s description.
Conclusion
Understanding the interaction between spells and AC is crucial for any spellcaster in D&D 5e. Remember, not all spells target AC. Many require saving throws, a different type of mechanic altogether. By carefully reading spell descriptions and understanding the core rules of spellcasting, you’ll be well-prepared to navigate the battlefield and unleash powerful spells on your foes.