What Is a Proficiency Bonus in D&D and How Does It Work?

What Is a Proficiency Bonus in D&D and How Does It Work?

All D&D characters get a proficiency bonus, even monsters, and the size of that bonus increases as the character levels up. So far, so good, right? However, it doesn’t get added to every throw and it can be confusing to figure out how to calculate it and when to add it. In this guide, we’ll dive deeper into what that proficiency bonus is and then talk about how to use it.

What Is a Proficiency Bonus?

Simply put: the proficiency bonus in Dungeons and Dragons is a bonus added to skill checks, saving throws, or attacks for skills that a character is proficient in. At first glance, it might not be obvious how this bonus differs from the ability modifiers a character has.

The key difference is that the bonus only applies in select cases. While an intelligence modifier will get added anytime that character is doing something that requires intelligence, a proficiency bonus is only added if that character has added proficiency for the specific skill or tool required. This means that the character either has a natural talent with this particular action due to their class and race or that they’ve spent extra time training and leveling up this skill.

For example, a rogue will have a natural proficiency with thieves’ tools while a Bard would have a natural instinct for musical instruments. In a battle of the bands between the two, the bard is going to have an advantage. In a high stakes heist scenario, the rogue is going to have the advantage.

For the purpose of the game, you express that unique advantage as the proficiency bonus. This is a specific number of points that will get added to the player’s throw any time they are doing something that their character is uniquely proficient in.

How Is It Calculated?

The value of a character’s proficiency bonus is tied to their level so it’s easy to figure out how much of a bonus they get. All level 1 characters, regardless of class or race, get a +2 proficiency bonus. At level 5, the bonus increases to +3. It continues to increase until it reaches +6 at level 17.

Adding the Proficiency Bonus to a Roll

To calculate the total points on a roll, simply add the ability modifier and the proficiency bonus to the dice. For example, say you have a level 3 elf with a wisdom of 16 who rolled an 11 on their perception check. Here’s how you’d calculate that:

11 (base roll) + 3 (Wisdom modifier) + 2 (proficiency bonus) = 16

You only add the proficiency bonus once, even if the character has two or more proficiencies that would help them in this action. The only exception to this is when a character has class-based expertise. In that case, the proficiency bonus is doubled.

This usually happens with rogues or bards who are able to apply an expertise feat to one or two skills, but other characters can have expertise in special circumstances. For example, a draconic sorcerer would get an expertise feat in charisma if they’re talking to a dragon of the same type as themselves. However, these situations are rare and mostly subject to your approval as the GM.

Multiclass Proficiencies

In D&D proficiencies are largely defined by class. But what if you’ve got a character with two classes? In this case, the proficiency bonus is based on the overall character level, not the level of the class the proficiency comes from.

So, a multiclass character who’s a level 5 monk/level 3 rogue has an overall character level of 8. That means their proficiency bonus is +3 regardless of whether they’re using a monk class proficiency or a rogue class proficiency.

When Do You Use It?

The proficiency bonus only applies when the character is attempting something that they are uniquely good at. That includes the following scenarios:

  • Attack rolls with weapons the character is proficient with or spells the character casts
  • Ability checks using tools or skills that the character is proficient in
  • Saving throws using abilities the character is proficient in or DCs for spells the character casts

For example, a character with an athletics proficiency will get a proficiency bonus whenever doing something that requires athletic skill.

Let’s say you’ve got two characters walking through a forest. One is a lean and agile ranger. The other is a big, hulking barbarian. While walking, they happen upon a large pit. They decide that walking around it would take too long so they want to jump across it instead.

For the sake of our example, let’s say they both have the same strength modifier. However, the ranger, who is proficient in athletics and therefore better at long jumps, would get a proficiency bonus here on top of their strength modifier. The barbarian, on the other hand, will just have to take a leap of faith.

Don’t Add a Proficiency Bonus to Damage or Healing Throws

While the bonus can be added to attacks, saves, and ability checks, it cannot be added to damage or healing throws. A character’s proficiency in a skill only increases in their odds of succeeding in the attempt. It does not add to the damage done in an attack or to the amount of HP restored when healing.


By Rachael Green, contributing Dice Dungeons blogger.

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