Mechanique de Arcane (5e Subclass)
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The Rogue Mechanic is more interested in how things work than actually creating them. An expert at taking things apart and figuring out how they work, gives them a distinct advantage to interacting with them, even magical creations. Your fascination with man made items is often mistaken for obsession. Every successful Rogue Mechanic puts themselves at risk to become lost in their work one day. Literally.
At level 3, you can add +1 for each round you study an object (up to your INT bonus maximum) that can be used to Disarm, Dismantle, Unlock, Investigate or interact with, devices, clockwork items and creatures, constructs, magical and mechanical items.
At 3rd level, you learn how to communicate with, read or understand devices, clockwork items and creatures, constructs and mechanical items. Whether by handling it, speaking to it or deciphering it’s clicks and whirrs, you just have the knack for comprehending motives, built in instructions or communications of any type when it pertains to items. What you can learn from a simple lock might be who made it. From more complex creations actual speech or mechanical relays project inner workings and commands or intent. If the item can receive instructions it can be questioned the way an animal might be questioned by a Druid that can speak with animals. The most complex creations that can think or process information (Warforged, golems, etc), can communicate with the Mechanic as it would with it’s own creator. Items that don’t have a built in means of communication must be interacted with (such as touched) to reveal it’s secrets as a discovery. The things ability to communicate does not necessarily mean the creature is willing, but using the Student ability, persuading it to cooperate has an increased chance the longer you interact with it (up to your INT bonus maximum).
At level 9, the Mechanic can alter the purpose of less complex items or reprogram more complex items similar to the Geas spell but it only works on items/creations that can be given or have been given instructions or an intelligent purpose. If the item has a destruct mechanism it can be commanded to self-destruct, otherwise it will simply shut down. This works against non-living, not undead complex devices, clockwork items and creatures, constructs, magical and mechanical items. While it is possible (with Tick Tock) to understand the purpose of a relatively simple item like a magic wand, altering the purpose of a singular use item may be a simple as exchanging one property for another (range for charges, or charges for duration, etc). Being able to reprogram something doesn’t necessarily mean you have the skill to use it. Just like repairing a broken crossbow doesn’t mean you can shoot and hit something with it if you tried. The Mechanic must be able to interact with the device to perform this function (e.g. Tick Tock ability, control mechanism, touch or combinations of these).
If the item has a semblance of intelligence it may attempt to make a save vs. INT to resist the programming. If it fails, the new program is in effect until undone with a new programming, remove curse, greater restoration or wish spell. If the item tries to go against the new program it takes 5d10 internal damage. Casting range is Touch, Verbal and Somatic components, takes 1 minute to cast.
At level 13 you can unlock, disarm, dismantle or render useless (deactivate) devices, clockwork items and creatures, constructs, magical and mechanical items simply by touching it. The object makes a CON save at a disadvantage minus your INT bonus or be rendered deactivated, disarmed, unlocked or dismantled according to the desire of the Mechanic. Thieves tools are no longer required to perform thieving abilities but you must touch or otherwise interact with the device then make your skill check (Student bonuses available if you spend time studying it first).
Ghost in the Shell (Possess)
When you reach 17th level you become one with the things you’ve studied your entire life and you gain the ability to (once per long rest) possess a non-living, not undead creature or complex devices, clockwork item or creature, construct, magical or mechanical item you touch. Your body becomes an immaterial force that possesses the thing and you now control it. You gain access to all of it’s abilities, your Tick Tock ability gives you access to it’s memories, programming and knowledge. You substitute your STR, DEX and CON for it’s, you retain your INT, WIS and CHA. You can only be ejected by Psychic damage taken from your temporary hit point pool (or technically an exorcism spell I guess). If you take enough Psychic damage to reduce your temporary hit point pool to zero hit points or lower (excess of your temp pool is taken as physical damage as you’re forcibly ejected from the item), your immaterial force is knocked out of the object and returns to material form nearby. Leaving the thing is a simple action that can be done with the Rogue extra action ability. If the thing itself is reduced to zero hit points or otherwise (somehow) shut down, you may leave the possession reflexively. Destruction of the item while still possessing it results in a psychic backlash, any damage over and above your temporary hit point pool is taken as physical damage as you’re forcibly ejected back into the your material form. Save vs. DEATH or be stunned for the number of rounds you failed the roll by. The duration of this ability is until ended through choice or circumstance. Long term possession risks the Mechanic losing their desire to return to mortal form at all. Every day of the possession, the Mechanic must make a WIS save. If they fail three successive checks (counter resets if they succeed), they can no longer choose to leave the device of their own volition. They must either be tricked, coerced, charmed or forcibly ejected else they refuse to go back to their normal lives. Rumor has it that some of the more powerful magic devices are exactly that; a Mechanic who has lost themselves to the perfection of a created life.