Trapper

You have become adept at finding, disarming, and using traps to your advantage. Rogues who embrace this archetype are capable of creating and modifying traps for use in battle. They are comfortable exploring alone in ruins with a network of traps set around them, or supporting their allies, preventing enemies from taking certain routes.

Bonus Proficiencies

When you choose this archetype at 3rd level, you gain proficiency in Tinkers’ Tools.

Keen Eye

At 3rd Level, you gain an unnatural ability to find and disarm traps. Whenever you make an Intelligence or Wisdom check to find a trap, treat a roll of 7 or lower on the d20 as an 8. This also applies to Dexterity rolls made to disarm a trap.

Trap Modification

When this archetype is chosen at 3rd level, you can expertly modify and create traps that are more deadly than their normal counterparts. Traps that affect a single target and do damage, that are modified or created by you, do additional damage equal to your sneak attack dice and are more difficult to spot or disarm.

Trap save DC = 8 + your proficiency bonus + your Intelligence Modifier

Trap Attack Modifier = your proficiency bonus + your Intelligence Modifier

Recycler

Starting at 9th level, you become even more adept at disarming traps, that sometimes you can salvage parts or even the whole trap. Depending on the type of trap a successful Dexterity check with thieves’ tools made to disarm the trap will enable you to use the parts to build a similar trap, or salvage it entirely to use as is.

Spell Sapper

Not all traps are mechanical or physical in nature. Some are made with magic and are much harder to discern to the naked eye. 

At 13th level, you have learned how to dispel or alter such magical traps. To dispel a magical trap, ward, or lock the Trapper must make an Intelligence(Thieves’ Tolls) check. The DC to succeed is equal to that of the spell within the trap, or that of the original spellcaster. Additionally, if the trapper succeeds by 5 or more they can alter specific elements of the spell instead of disarming it. They can either change the password if one is required, change the trigger to a trigger of their choice, or change the targets to targets of their choice if any are required.

Minefield Mastermind

At 17th level, you have learned to use your traps to support your companions in battle more effectively. When you take an action to set a trap you can instead set two at the same time. Additionally, you and your allies have advantage on attacks against targets that were affected by one of your traps until the start of their next turn.