Kobolds make their homes beneath the mountains, living in darkness most of their lives. While some may venture up to the surface, others will use their ingenuity to burrow further into the earth to reap the rich mineral bounties. The finest kobold engineering makes use of instruments such as massive drills which tear through rock at alarming pace.
The tunneler is an archetype of the engineer class, available only to kobold engineers.
Archetype Main Ability Scores:
The tunneler mainly focuses on STR for martial combat and INT for their class features.
Limit Break (Su)
At 1st level, the tunneler receives the Limit Break (Gigas Drill Breaker).
Gigas Drill Breaker (Su): This Limit Break allows the tunneler to perform a free Sunder combat maneuver against any foe he attacks. These Sunder maneuvers use the same attack bonuses and penalties as the attack for calculating the CMB, as well as any other bonuses to Sunder maneuvers the tunneler has. In addition, these attacks and combat maneuvers ignore an amount of DR and hardness of 2 + 2 per four engineer levels after 1st. This ability lasts for a duration of 1 round + 1 round per four engineer levels after 1st. This limit break requires only a swift action.
This ability replaces the Limit Break (Auto-Repair).
Power Drill (Ex)
At 2nd level, the tunneler can create a special gadget; a large drill attached to a pole that is suitable for a medium-sized creature to use as a 2-handed weapon. This is considered an exotic weapon with which the tunneler is proficient. The power drill deals 2d6 piercing damage, has 19-20 threat range, 2x damage on critical hits, has the brace special quality, and weighs 9 pounds.
The drill can be hand-operated when the tunneler wields it as a weapon using both hands. As a swift action, he may start spinning the drill. The tunneler’s power drill will stop spinning if it is not spun for 1 round, but he may maintain the current spin as a free action while wielding it. While spinning the drill, the tunneler improves his burrow speed up to his base land speed, using the drill to tunnel through even the hardest of materials. He may also charge and run using this improved burrow speed. The drill leaves behind a 5-foot diameter tunnel suitable for a medium creature to pass through. The operation of the drill while burrowing is noisy and causes vibrations in the earth. Creatures standing within 60 feet of the power drill’s tunneling may notice the ground rumbling, gaining a +8 circumstance bonus to Perception checks to notice the drill being used.
This ability replaces an engineer trick gained at 2nd level.
Rend, Split, Break (Ex)
At 4th level, the tunneler gains Improved Sunder as a bonus feat. He does not need to meet the requirements for this feat. If he already has the Improved Sunder feat, he may select a bonus combat feat for which he meets the requirements. In addition, the tunneler may add his Intelligence modifier to combat maneuver rolls and damage rolls to sunder equipment when spinning his power drill.
This ability replaces jury-rig.
Topple, Collapse, Cave-In (Ex)
At 8th level, the tunneler can cause any tunnel he burrows with his power drill to collapse behind him as he digs, choosing to have his burrowing treated as earth glide. He is not in any danger from falling rocks, but can only leave enough extra room for a single small creature to travel behind him while moving.
This ability replaces durable materials.
Breathing Apparatus (Ex)
Also, at 8th level, the tunneler can create a gadget that stores breathable air in a compressed tank, worn on his back slot. Each tank of compressed air weighs 25 pounds and provides 30 minutes of breathable air. The breathing apparatus’ face mask will shield the tunneler from toxic gases as a gas mask, as well as allowing him to breath clean air while underwater or in a collapsed tunnel. Due to the extremely high air pressure needed for the tanks, an empty tank requires 8 hours of work to be refilled with a hand compressor, or 30 minutes of work with an air compressor gadget.
This ability replaces an engineer trick gained at 8th level.
Break the Unbreakable (Ex)
At 20th level, the tunneler can gain a +20 equipment bonus on a single combat maneuver roll to sunder equipment with his power drill. He may use this ability up to 3 times per day.
This ability replaces one with machines.