On the go? Listen to the audio version of the article here:
It’s D&D night, and the party has been trudging through the wilderness for days. The ranger at the front rolls a Wisdom (Survival) check to navigate the way forward. The cleric rolls a Wisdom (Perception) check to listen for wild animals. The party rolls a Dexterity (Stealth) check to keep quiet after hearing a growling in the distance. When you make a skill check in D&D 5e, what are you aiming to roll? How does the Dungeon Master (DM) know if you’ve succeeded or not?
When rolling an ability check or saving throw in D&D, success is determined by reaching a predecided number called a Difficulty Class (DC). Some DCs are already set by certain monster or character stats, while others are made by the DM at the table. But how do you set them?
Let’s take a look at the general mechanics.
What is a DC?
For every ability check or saving throw, the DC is the number that you are trying to meet or beat after rolling a d20 and adding appropriate modifiers. If you do not roll high enough to meet the DC, the check fails, and if you meet or exceed it, you succeed.
The more difficult a check is, the higher its DC will be. According to the Player’s Handbook (PHB, pg. 174), typical difficulty classes are as follows:
Typical Difficulty Classes
When an ability check is called for in the game, the DM decides what the DC is depending on the difficulty of what is being accomplished.
The DC can be any number; it doesn’t have to be a multiple of 5. However, the above table signposts typical difficulty. For example, if the DM thinks that the check is somewhere between Easy and Medium, they might set a DC of 13.
The ranger tracking through the wilderness is following a path. When they make a Wisdom (Survival) check, it might be a DC10 check, meaning they have to get at least a 10 with the roll and all the modifiers..
The cleric is trying to listen for wild animals who don’t want to be found. This could be a DC20 Wisdom (Perception) check.
DMs don’t need to tell you what the DC of the check is before (or even after) you roll, so it can be hard to know what your chance of success is. However, if you or allies are creative in making the check more likely to succeed, the DM might grant you advantage on the roll or lower the DC of the check.
For example, if you are making a Strength (Athletics) check to climb a wall and an ally gives you a leg up, the DM might lower the DC from 15 to 10. Some extend the help action outside of combat, allowing for advantage in many non-combat situations.
As a DM, it is important to have a clear DC set before your players roll, otherwise you’ll be sitting there wondering whether the 14 your player just rolled is enough or not. For added drama, tell your players what the DC is and watch them freak out as they roll.
Sometimes the DM will call for a group check. These are similar to ability checks, but they are made by multiple people, such as when the entire party is sneaking through the wilderness. The DM calls for the check and sets the DC as usual.
Then all of the involved players roll the check, and if at least half the group meet or exceed the DC, then the whole group succeeds.
Sometimes the DM will call for a contested ability check. This occurs when you are attempting a skill check that is being opposed by another creature.
The most common examples of contested checks are grapples and stealth. In both cases, there is not a set DC that you are trying to meet when you make your roll. Instead, you are comparing the result of your ability check to the result of your opponent’s ability check.
You roll and add your modifier(s) while they roll and add theirs. If your result is higher than theirs, you have successfully grappled them. If their result is higher, they have escaped your grapple.
Similarly, when you roll a Dexterity (Stealth) check, it can be contested by an enemy’s Wisdom (Perception) check. If the result of your roll is higher, you are not spotted. If they roll higher, then you are. Though, there’s much more to be said on stealth; see our article here or our other one on passive perception.
Contested checks are the most volatile because the DC varies wildly. You can roll a 5 and potentially still win. Conversely, you could roll a 19 and still be beaten.
Looking to challenge your players?
Puzzles and Riddles can be tricky! Too easy and they’re pointless; Too hard and it’s pure frustration. What is a DM to do?
For easy-to-use resources for any D&D game, check out the selections at Dungeon Vault!
Spell Save DCs
Another common roll is a saving throw against a spell. If you cast a spell that requires a saving throw, the DM will roll for the target of the spell or for every NPC in the area of effect of the spell.
The DC for the saving throw against your spell is determined by your spellcasting ability. At the top of the spell page of your character sheet, there is a box labelled “Spell Save DC”. This number is equal to:
- 8 + your proficiency bonus + your spellcasting modifier.
The three creatures caught in the area of effect of the Thunderwave must make a Constitution saving throw against the bard’s spell save DC. This DC is equal to:
- 8 + 2 (proficiency bonus at 2nd level) + 3 (Charisma modifier) = 13.
The DM rolls three DC13 Constitution saving throws. After adding modifiers, they rolled a 15, a 12, and a 1. The roll above 13 succeeded the check while the other two failed.
The two creatures that failed will experience the full effect of the spell, while the creature who succeeded takes only a portion of the effect, according to the spell’s description.
Attack Rolls and Armor Class
Similar to ability checks vs DC, when you roll an attack against a creature, you are rolling against their target’s Armor Class (AC). When enemies attack you, the DM rolls and will ask something like, “does a 15 hit you?”
The answer to this depends on your AC. Your AC is determined by the armor that you’re wearing, often with your dexterity bonus. In this case, you look at your character sheet and see that your AC is 15. Since the attack roll meets your AC, it does indeed hit you. It’s still meet-or-beat, like many things in 5e.
Similar to DCs, you don’t always know what an enemy’s AC is but over the course of a battle, you can narrow it down based on the rolls that hit and the ones that don’t.
- When making an ability check or saving throw, success is determined by meeting or exceeding the Difficulty Class (DC) of the roll. The harder the check, the higher the DC.
- You don’t always know the DC of the check before you roll, but if you’re a DM, you need to decide what the DC is before your players roll.
- Group checks require at least half the group to meet or exceed the DC for the whole group to succeed.
- Contested checks occur when opposed by another creature. In this case, the DC is the ability check your opponent makes.
- The DC for spell effects is dependent on the spellcaster, and the spell DC equals:
- 8 + proficiency bonus + spellcasting modifier.
- Armor Class (AC) is the DC for attack rolls made for both weapons and spells.
- With all ability checks, saving throws, and attack rolls, if the roll is equal or greater than the DC, the check succeeds.