When I was a green adventurer, I thought “proficiency” just meant not dropping your sword on your foot. Turns out, it’s a bit more structured than that.
In Dungeons & Dragons 5e, your proficiency bonus is a small number that makes a big difference. It’s tied to your character’s experience and training—and it quietly fuels most of your rolls, from attacks and skill checks to saving throws and tools.
Let’s break down exactly what a proficiency bonus is, when you add it, and why it matters more than you might think.
What Is Proficiency Bonus in D&D 5e?
Your proficiency bonus is a flat number added to certain rolls where your character is trained or skilled.
You start with a +2 at level 1, and it increases as you gain levels:
| Character Level | Proficiency Bonus |
|---|---|
| 1–4 | +2 |
| 5–8 | +3 |
| 9–12 | +4 |
| 13–16 | +5 |
| 17–20 | +6 |
So if you’re level 3, your proficiency bonus is +2. When you reach level 5, it becomes +3—and so on.
When Do You Add Your Proficiency Bonus?
You don’t add your proficiency bonus to every roll—only to actions your character is trained in.
Here’s where it applies:
- Attack Rolls: When using weapons you’re proficient with
- Saving Throws: Only the ones your class is proficient in
- Skill Checks: For skills you’re proficient in (like Stealth or Persuasion)
- Tools: If you’re proficient with a toolset (like Thieves’ Tools or a Brewer’s Kit)
- Spell Attacks & Save DCs: If you’re a spellcaster, your spellcasting ability is tied to proficiency
Think of it as your competence bonus—it represents the stuff your character knows how to do well.
How Is Proficiency Bonus Different From Ability Modifiers?
This is where folks get tangled up.
Let’s say you roll a Persuasion check and your Charisma modifier is +3. If you’re proficient in Persuasion and your proficiency bonus is +2, your total modifier is:
+3 (Charisma) +2 (Proficiency) = +5
But if you’re not proficient in Persuasion, you’d only add the +3 from Charisma.
So your proficiency bonus stacks with your ability score modifiers, but only when you’re trained in that skill or action.
How to Know What You’re Proficient In
It’s on your character sheet, but here’s a breakdown by area:
- Weapons and Armour: Your class defines what gear you’re proficient with.
- Saving Throws: Each class has two specific saves you’re trained in.
- Skills: Chosen at character creation or granted by background/class.
- Tools/Languages: Often from your background or race.
- Spells: If you can cast spells, your proficiency affects your Spell Attack Bonus and Spell Save DC.
Check out your class and background features to see what’s listed.
For example:
- A fighter is proficient in Strength and Constitution saving throws.
- A rogue might be proficient in Stealth, Sleight of Hand, and Acrobatics.
- A wizard has Intelligence-based skills and is proficient in Arcana.
Proficiency Bonus and Expertise
Some classes—like rogues and bards—can gain expertise, which lets them double their proficiency bonus on certain checks.
So if your proficiency bonus is +2, and you have expertise in Stealth, you add +4 instead of +2 to your Stealth checks.
This makes rogues terrifyingly good at sneaking and stealing.
Tips for Using Proficiency Bonus Effectively
- Pick proficiencies that match your character concept (Don’t waste Athletics on a wizard).
- Remember to apply it—it’s easy to forget proficiency on tool checks or saving throws.
- Plan ahead—as your bonus grows, so does your effectiveness in key skills.
If you’re unsure how to assign or build around your stats and modifiers, check out our Mastering Ability Scores guide or see example builds in First Character Builds.
Final Thoughts
Your proficiency bonus is small but mighty. It’s the edge that turns a lucky roll into a guaranteed hit, or a clutch save into a character-defining moment.
Don’t overlook it. Understand it. Use it. And build your character around the things they do best.
Now get out there, roll the dice, and show the world what you’re good at.
— Mike “Silver-Tongue”
