As the Thief, it’s on you to get the party through locked doors. Here’s a clear breakdown of the essentials.
Doors
To open a door, use the Utilize Action. For us Thieves, it’s a Bonus Action.
Some doors may pose extra challenges. For more detail, check the DMG 2024 - Doors section.
- Locked? Head down to the Locks section. - Stuck? Pass a Crowbar to the Fighter. Using it gives them Advantage on the Strength check—not exactly heroic, but it’s just a door. Hopefully, not their most memorable battle.
For unusual doors, anything’s possible. You may need Arcana, puzzle-solving, or a good dose of creativity. Dungeon design is quirky; roll with it.
Locks
Locks are the main obstacle you’ll face, so here’s what you need to know.
Lock: > A Lock comes with a key. Without the key, a creature can use Thieves’ Tools to pick this Lock with a successful DC 15 Dexterity (Sleight of Hand) check.
This looks straightforward, but let’s go through each detail.
Every Lock Has a Key
Simple enough: if there’s a lock, there’s a key somewhere. It may be on a nearby person or hidden in a close room.
Why go for the key? Using the key: - Won't trigger traps or alarms - Leaves no trace - Allows you to lock it again afterward
Using the key should always be your first choice.
Picking the Lock
When the key’s nowhere to be found, it’s time to pick. Here’s how to approach it.
Thieves' Tools: > Ability: Dexterity > Use: Pick a lock (DC 15) or disarm a trap (DC 15)
Lock: > A creature can use Thieves’ Tools to pick this Lock with a successful DC 15 Dexterity (Sleight of Hand) check.
Tool Proficiency > If you have proficiency with a tool, add your Proficiency Bonus to any ability check you make that uses the tool. If you have proficiency in a skill that’s used with that check, you have Advantage on the check too.
Thief: Fast Hands > Make a Dexterity (Sleight of Hand) check to pick a lock or disarm a trap with Thieves’ Tools or to pick a pocket.
Summary
- Without Thieves' Tools, you cannot pick a lock. - You can attempt to pick a lock without any proficiency, using a basic Dexterity check. - If you have proficiency with Thieves' Tools, add your Proficiency Bonus to the Dexterity check. - If you have proficiency in Sleight of Hand, you should roll a Dexterity (Sleight of Hand) check instead. - If you have both Sleight of Hand and Thieves' Tools proficiency, you roll a Dexterity (Sleight of Hand) check with advantage. - At Level 3, Thieves can pick a lock using either an Action or a Bonus Action.
Success Rate Analysis
I’d like to evaluate the usefulness of investing in Sleight of Hand for opening locks. As a Thief, we already have proficiency with Thieves' Tools, so our base modifier for lockpicking attempts includes DEX + Proficiency Bonus.
For this analysis, I’ll assume our Dexterity progresses as follows: 17 DEX at Level 1, 18 DEX at Level 6, and 20 DEX at Level 12.
The table below outlines various Lock DCs and the associated success percentages. According to the Dungeon Master's Guide - Lock Quality, typical Lock DCs range from 10 to 20. However, DCs of 25 and 30 represent particularly rare and challenging locks you might encounter in extraordinary circumstances.
At level 7, we get Reliable Talent, which will allow us to succeed at picking some locks automatically.
I used d20calc.com to determine these success percentages.
As you can see in the tables below, what matters is Sleight of Hand proficiency. From Levels 1 to 6, Sleight of Hand proficiency is clearly enough to allow us to open most locks we encounter. At Level 7, Reliable Talent ensures you'll automatically succeed on checks to unlock Inferior (DC 10) and Good (DC 15) locks. For Superior Locks (DC 20), you have a 64% chance of success. As far as lock-picking goes, Expertise in Sleight of Hand is definitely not worth it.
This post is part of Firemind’s Thief Handbook: 2024+ Edition—a comprehensive guide for the Thief subclass.
Doors & Locks
As the Thief, it’s on you to get the party through locked doors. Here’s a clear breakdown of the essentials.
Doors
To open a door, use the Utilize Action. For us Thieves, it’s a Bonus Action.
Some doors may pose extra challenges. For more detail, check the DMG 2024 - Doors section.
- Locked? Head down to the Locks section.
- Stuck? Pass a Crowbar to the Fighter. Using it gives them Advantage on the Strength check—not exactly heroic, but it’s just a door. Hopefully, not their most memorable battle.
For unusual doors, anything’s possible. You may need Arcana, puzzle-solving, or a good dose of creativity. Dungeon design is quirky; roll with it.
Locks
Locks are the main obstacle you’ll face, so here’s what you need to know.
Lock:
> A Lock comes with a key. Without the key, a creature can use Thieves’ Tools to pick this Lock with a successful DC 15 Dexterity (Sleight of Hand) check.
This looks straightforward, but let’s go through each detail.
Every Lock Has a Key
Simple enough: if there’s a lock, there’s a key somewhere. It may be on a nearby person or hidden in a close room.
Why go for the key? Using the key:
- Won't trigger traps or alarms
- Leaves no trace
- Allows you to lock it again afterward
Using the key should always be your first choice.
Picking the Lock
When the key’s nowhere to be found, it’s time to pick. Here’s how to approach it.
Thieves' Tools:
> Ability: Dexterity
> Use: Pick a lock (DC 15) or disarm a trap (DC 15)
Lock:
> A creature can use Thieves’ Tools to pick this Lock with a successful DC 15 Dexterity (Sleight of Hand) check.
Tool Proficiency
> If you have proficiency with a tool, add your Proficiency Bonus to any ability check you make that uses the tool. If you have proficiency in a skill that’s used with that check, you have Advantage on the check too.
Thief: Fast Hands
> Make a Dexterity (Sleight of Hand) check to pick a lock or disarm a trap with Thieves’ Tools or to pick a pocket.
Summary
- Without Thieves' Tools, you cannot pick a lock.
- You can attempt to pick a lock without any proficiency, using a basic Dexterity check.
- If you have proficiency with Thieves' Tools, add your Proficiency Bonus to the Dexterity check.
- If you have proficiency in Sleight of Hand, you should roll a Dexterity (Sleight of Hand) check instead.
- If you have both Sleight of Hand and Thieves' Tools proficiency, you roll a Dexterity (Sleight of Hand) check with advantage.
- At Level 3, Thieves can pick a lock using either an Action or a Bonus Action.
Success Rate Analysis
I’d like to evaluate the usefulness of investing in Sleight of Hand for opening locks. As a Thief, we already have proficiency with Thieves' Tools, so our base modifier for lockpicking attempts includes DEX + Proficiency Bonus.
For this analysis, I’ll assume our Dexterity progresses as follows: 17 DEX at Level 1, 18 DEX at Level 6, and 20 DEX at Level 12.
The table below outlines various Lock DCs and the associated success percentages. According to the Dungeon Master's Guide - Lock Quality, typical Lock DCs range from 10 to 20. However, DCs of 25 and 30 represent particularly rare and challenging locks you might encounter in extraordinary circumstances.
At level 7, we get Reliable Talent, which will allow us to succeed at picking some locks automatically.
I used d20calc.com to determine these success percentages.
As you can see in the tables below, what matters is Sleight of Hand proficiency. From Levels 1 to 6, Sleight of Hand proficiency is clearly enough to allow us to open most locks we encounter. At Level 7, Reliable Talent ensures you'll automatically succeed on checks to unlock Inferior (DC 10) and Good (DC 15) locks. For Superior Locks (DC 20), you have a 64% chance of success. As far as lock-picking goes, Expertise in Sleight of Hand is definitely not worth it.