3: Cunning Trap, Trap Sense, Trapmaking, Bonus Expertise
9: Augmented Trapmaking
13: Improvised Crafting
17: Deadly Trapmaking
When you choose this archetype at 3rd level, you gain two skill points to spend in Dungeoneering and/or Thievery, and you gain an expertise die on checks made with either. For you, expertise dice in these skills can be upgraded from d8 to d10, exceeding the usual limit on expertise dice.
Starting at 3rd level, you can use your Cunning Action to spread caltrops or ball bearings, or to throw a vial containing holy water, acid, or the like. Vials are simple weapons for you and have the thrown property (20/40 feet).
Also at 3rd level, you have advantage on saving throws made against traps. Ability checks made to detect and disarm traps are made with advantage and can be made using your Cunning Action.
Beginning at 3rd level, with 10 minutes of work you can boobytrap a 5-footsquare area or a Large or smaller object. Your trap can be anything from a needle in a lock to a rockfall in a passageway. Describe the mechanics of your trap to the Narrator. Logic determines which traps can be built where; for instance, a swinging axe can’t be hidden in a jewelry box.
The trap’s DC is 8 + your Intelligence bonus + your proficiency bonus. A creature can spot the trap by making an Awareness check against the trap’s DC. Creatures aware of the trap may avoid or disable it without a check. When a creature enters the trapped area or interacts with the trapped object it must succeed on an Anchor or Reflex (determined by the Narrator) saving throw against the trap’s DC. On a failure, the trap is triggered and the creature takes an amount of damage equal to 1d6 damage times half your rogue level. The type of damage dealt (bludgeoning, piercing, slashing, or poison) is determined by the nature of your trap.
Once a trap has been triggered, it is disabled. You can use this feature a number of times equal to your proficiency bonus. You regain all uses of this feature when you finish a long rest.
At 9th level, you invent a new way to increase the danger posed by your traps. You learn one of the following trap capabilities. When using Trapmaking to create a trap, you can choose to augment it with the new capability, which is triggered when your trap damages a creature.
Immobilization Trap
The target is caught in the jaws of a trap. The target’s movement speed is reduced to 0. A creature can use an action or legendary action to make a Power check against your trap's DC, freeing itself or another creature on a success. Building this trap requires a hunting trap, which can be recovered after the trap is triggered.
Poison Trap
You may add a contact or injury poison to the trap, which is consumed. The victim of the trap is affected by the poison.
Vial Trap
Each creature within 5 feet of the trap must make a Reflex saving throw or be splashed with a liquid, such as acid or alchemists’ fire. The liquid is consumed.
Starting at 13th level, you can create a mundane item during a short or long rest. You can create one of the following items, which lasts until the beginning of the next long or short rest.
A vial of alchemist’s fire or acid.
Any weapon, ammunition, or gear which costs 20 gold or less (or several identical items with a total cost not exceeding 20 gold).
The item functions like the original object but may be made of different materials.
Starting at 17th level, the traps you create with your Trapmaking feature deal an amount of damage equal to 1d6 damage times your rogue level.