You can activate or deactivate your armor’s force field as a standard action. Once active, the device generates an invisible force field around you (a force effect), including all your worn and carried items. The force field blocks solids and liquids but not gases or light (including laser beams). You can breathe while the field is active, but you can’t eat or drink.
While a force field is active, it provides you with a number of temporary Hit Points depending on the force field’s power. A force field has fast healing, meaning that it regains temporary Hit Points at a fixed rate each round at the end of your turn, up to its normal maximum. If the force field’s temporary Hit Points are reduced to 0, it is inactive until the end of your next turn, when its fast healing restores some of its Hit Points. The charge capacity, amount of temporary Hit Points granted, and rate of fast healing vary according to the force field’s color code. A force field has a usage of 1 charge per round.
More powerful force fields also have a fortification ability, which gives a percentage chance that a critical hit is treated as a normal attack, dealing normal damage and not applying any critical effect. You roll your fortification percentage chance before the critical hit’s damage is rolled. If a force field is inactive, its fortification ability does not function. A suit of armor cannot support more than one force field upgrade.