Shayuri: Maybe a steam-pack that gives you a second or two of concealment or total concealment when activated (maybe a swift action to activate? or a free action once per round?), buying you a second to step aside so an incoming attack is more likely to miss.
Or a gadget-arm-shield-module thingamabob, that springs into this big, complicated, shield-like thing when activated, then compacts back into a smaller bundle when deactivated.
Or a sort of light exoskeleton armor-thing, that only provides partial protection (like leather armor instead of plate armor) but helps you move faster and stronger, for better speed, jumping, and melee attacks perhaps.
Or reactive studded leather armor; it works like studded leather, but the studs are replaced with strategically-placed small plates. If any of those plates is stricken, a steam-pack attached to the armor activates a wierd pneumatic device under the plate, springing it outward a few inches with a small burst of released steam, before retracting. The reactive property helps to try and repel the attack before the rest of the blade/striking end/whatever hits flesh. Probably clunkier than normal studded leather, but more effective sometimes. Probably mithral plates, to keep the weight down and only slightly heavier than normal studded leather.
Some idea for a mage: A wierd, supernatural, oversized beetle. It clings to you most of the time like some kind of creepy, dead accessory, but is in fact a living magivore/magiphage that thrives on the excess energy released by the spells you cast. So remains quiet and motionless most of the time, waiting for you to cast spells for it to leech a bit of excess energy off of (not enough to weaken the spell). And when you're attacked, it reacts with preternatural speed to scurry into place and try deflecting the attack with its superhard carapace, protecting its food source.
Better yet, it leeches a bit of energy off of offensive spells used against you (maybe just from area-effect spells, though), more actively than it does from your own spells, slightly weakening their negative effects upon you. Like, +2 to your saves against magic, or reducing the damage to you from magical attacks by 5 points or suchlike. Just an idea.
Mages often have a pointy hat, a cowl, a mantle, or a cloak. It could be their defensive item, protecting them from some forms of attack. A Pointy Hat of Mind Shielding and Critical Hit Aversion. A Mantle of Protection from Projectiles. A Cloak of Occasional Disappearance. A Cowl of Hypnotism. A Mask of Menacing.
Maybe a set of magic orbs, disks, or runestones, that fly about you when you're attacked, to try deflecting attacks or absorbing some spell energy.
