Adaptive Hypothesis

This armor has an Intelligence score of 16 and continuously analyzes incoming threats. Whenever you take damage from a creature, the armor logs the damage type. The first time you take damage of each logged type during the same combat encounter, you gain resistance to that damage type for the remainder of the encounter. You can have resistance to a maximum of three damage types simultaneously through this effect; if a fourth type would be added, you choose which one to drop. Resistance gained this way does not stack with resistance from other sources but does not interfere with it.

Kinetic Marginalia

Whenever you take bludgeoning, piercing, or slashing damage from a melee attack, the armor stores a portion of the kinetic force. You can accumulate up to 10 Theorem Points (TP) at a time; each time you take such melee damage, you gain TP equal to half the damage taken (rounded down, minimum 1), up to the cap. As a bonus action, you can expend any number of stored TP to release a concussive burst. All creatures within 10 feet of you must succeed on a Strength saving throw (DC 17) or be pushed 5 feet away from you for every 3 TP spent and knocked prone. On a successful save, they are pushed but not knocked prone. TP resets to 0 at the end of each combat encounter.

Theorem Engine

The armor has 6 charges. You can use the following abilities by expending charges. The armor regains 1d4 + 2 expended charges daily at dawn. • Postulate Shield (1 charge, reaction): When you or a creature within 30 feet of you would take damage, you reduce that damage by 2d10 + 5. If the damage is reduced to 0, the attacker takes 1d6 force damage as the stored energy reflects outward. • Field Revision (2 charges, action): The armor reconfigures its defensive plating for 1 minute. During this time, your AC increases by 2 and you have advantage on saving throws against spells and magical effects. This effect ends early if you are incapacitated. • Final Proof (3 charges, action): You unleash the armor's full analytical power. Choose a creature you can see within 60 feet. The armor calculates every gap in the target's defenses. Until the start of your next turn, attack rolls against the chosen creature have advantage, the creature cannot benefit from the dodge action, and each time the creature takes damage it takes an additional 2d8 force damage. At the end of your next turn, the armor vents residual energy in a 10-foot radius burst centered on you; each creature of your choice in that area must succeed on a Constitution saving throw (DC 17) or be stunned until the end of their next turn.

Perpetual Refinement

When you finish a long rest, you may review the armor's internal logs — a readable set of glowing runes on the interior lining describing every attack it absorbed during the previous day. You gain advantage on the first saving throw you make against any damage type the armor recorded during the previous 24 hours. Additionally, the armor counts as a set of artisan's tools (tinker's tools) for the purpose of crafting and the Artificer Infusions feature, and while wearing it you can cast the Identify spell as a ritual without requiring material components, once per short or long rest.

The Living Draft

The armor is always under construction. You can spend 1 hour of focused work (which can be done during a short rest) to retune one of the following passive properties of the armor until you retune it again: (a) your walking speed increases by 10 feet; (b) you gain darkvision out to 60 feet, or if you already have darkvision its range increases by 30 feet; (c) you have advantage on Investigation and Arcana checks; or (d) you ignore difficult terrain caused by debris, rubble, or mechanical hazards. Only one option can be active at a time.