Engineers that are builders are skilled at creating any sized object or physical structure. They have studied architecture, interior design, carpentry, masonry, and metalworking. A builder is responsible for the construction and repair of wood, concrete, masonry, or metal objects and structures.
At 1st level, you gain an advantage on all History and Physics checks on any object or physical structure, regardless of who made them. You can also know where to find blueprints of a specific building or structure in order to learn the details of its construction. This includes machines, such as mechs. Such blueprints might provide knowledge of entry points or secret spaces. Your access to such information isn’t unlimited.
At 3rd level, as an action you can instantly identify the physical flaws, structural weaknesses, or defects in any machine or physical structure. You can also determine if it meets the required specs for the desired use.
At 3rd level, and with the engineer's kit, you can repair any machine. It will regain 1D4 + Wisdom score in hull points with each hour worth of work. At 9th level, the machine regains 1D6 + Wisdom score.
At 6th level, with your engineer’s kit and 6 hours, you can build either a guardian droid or a battle droid. Both are machines that are the equivalent to a medium-sized beast and built to defend you and your allies (guardian) or engage enemies (battle). They are loyal to you, obeying only your commands, and friendly to your allies. You determine their appearance and whether they have two or four legs. Their base movement speed is 30 feet. At 8th level, you can build them with wings or fins, allowing them to either fly or swim. Their movement remains the same. At 10th level, base speed increases to 40 feet. At 12th level it takes you 2 hours to construct a droid.
In combat, the droids share your initiative count, but they take their turn immediately after yours. They can move and use their reaction on their own. Among their own actions, they can take the dodge, thrust, help, hide, or search actions.
You are able to repair them with an engineer’s kit, and they will regain 2D4 + your Wisdom score in hull points, 2D6 + your Wisdom score in health points at 10th level, and 2D8 + your Wisdom score in health points at 12th level. You can do this once per short rest.
At the end of a long rest, you can create a new droid if you have your engineer’s kit with you. If you have already built a droid, the first one immediately perishes. You are able to have two at 15th level. You can destroy the droids at any time.
Your droids are large enough to mount, both in combat and out. While mounted, the droids can take half the damage against you on your reaction. The droids can not take psychic or radiation damage, unless otherwise stated in their stats. They are resistant to damage from non magical blades.
At 9th level, and while operating a mech, you can enhance your mech’s engines. Add +1 to Engines score. At 15th level, add an additional +1 to Engines score.
At 18th level, all activities that required a long rest between tasks, now only require a short rest. Any mech you operate only needs to reboot in order to gain the benefits of a shutdown.