Steampunk Mechanist

You have delved deep into the art of tinkering, using scientific and mechanical knowledge to augment your weapons and abilities to create wonderful and deadly affects, pushing the boundaries of what's considered possible; even by arcane standards. Rogues who fit this archetype often made their start as blacksmiths, or aspiring inventors with too much time on their hands.

Mechanical Knowledge

When you select this archetype at level 3, you can use your bonus action to make a DC 10 intelligence check to study a creature's armor to pinpoint its weak spots. On a successful check, your next attack against that creature is made with advantage. This ability has no effect on creature is not wearing armor. 

 

You may use this ability a number of times equal to your intelligence modifier per short or long rest. 

Weapon Upgrades

Starting at level 3, you gain the ability to augment certain weapons to better fit your fighting style. You gain access to the following upgrade paths as well as proficiency with tinker's tools. Upgrading a weapon takes a number of hours equal to 8 minus your intelligence modifier, as well as 3d4 (or 8) gp per hour of work. You can only have 1 upgrade on a weapon at a time. 

Accuracy Scope

You add well-measured sights or scopes to a ranged weapon. When you make a ranged attack with that weapon, you gain a +2 bonus to attack rolls. Additionally, you can use your bonus action to focus your gaze down the sights. When you do so, long ranged attacks are no longer made with disadvantage. 

Lightning Blade

You upgrade a melee weapon of your choice to do additional lightning damage equal to your intelligence modifier or your proficiency bonus, whichever is higher. You can activate this effect as part of your attack action, which lasts for 1 round and can be used a number of times equal to your intelligence modifier per short or long rest, where you must spend an hour recharging it's power source.

Repeating Crossbow

You upgrade a crossbow, allowing it to fire an additional bolt when you take the attack action. You make separate attack rolls for each bolt. when you reach level 9 you may upgrade your crossbow a second time, allowing it to fire a 3rd bolt. 

Steampunk Innovations

When you reach 9th level you gain the ability to create completely new designs. Forging a design takes a number of hours equal to 12 minus your intelligence modifier, as well as 5d4 (or 13) gp per hour you take.

Electromagnetic Field

You create a small handheld device, that emits a powerful electromagnetic wavelength. This device can be stowed or clipped to a piece of equipment. You gain +1 to your AC while this device is equipped, as well as resistance to 1 damage type of your choosing, depending on it's frequency. You may use your action to move the dial to frequency and choose a different damage type.

Flamethrower

You may use your action to ignite your flamethrower. All creatures within a 15 foot cone must succeed a dexterity saving throw. The save DC is 8 + your proficiency bonus + your intelligence modifier. On a failed save they take 3d6 fire damage, and half damage on a successful one. This weapon can be used a number of times equal to your intelligence modifier before you must add another pint of oil. Doing so takes 1 minute. 

Mechanical Wings

Donning or a set of mechanical wings takes 1 action, and you gain a flying speed of 60 feet while they're equipped, as long as you aren't wearing medium or heavy armor. Your wings take any form you choose, and weigh 20 lbs. Your wings have an AC of 14, and 16 hit points. A creature can choose to make an attack against your wings instead of you, and if they are reduced to zero hit points they cease to function until you spend an hour repairing them with your tinker's tools. 

Reliable Assumptions

Upon reaching 13th level you have studied a wide a variety of trades and topics. When you make a skill check using tools that you are not proficient in, you can add your proficiency bonus anyway.

Once you use this you cannot use it again until you finish a long rest.

Mechanical Machinations

Through practice of tinkering and in depth studying, you've learned the more complex fundamentals of the inner workings of constructs. When you reach 17th level, you may make a dexterity (tinker's tools) check against a construct's wisdom saving throw as an action. If the construct is hostile, and you don't have an alley within 5 feet of it, the construct gets to take an opportunity attack on you. The construct must have a challenge rating of 2 or lower, and you must be in melee range with it. On a failed save, the construct becomes under your control, or shuts down (your choice). While under your control the construct will obey your commands to the best of its capabilities, and will be hostile to your enemies. If the construct shuts down it becomes paralyzed. This effect lasts for 1 hour, after which the construct will began acting normally.