Accuracy X/-X: A cumulative, static ability that means, "Add X to each of this unit’s attack dice." and "Subtract X from each of this unit’s attack dice." respectively. Accuracy can’t alter "natural" rolls to affect Critical Hit, Fury, or Parry, but it can affect your chance against Armor. If a unit gets the Accuracy ability after you roll attack dice, it's too late to affect the hits.
Ambush
Ambush X: A layered, activated ability that means, "If your opponent deploys, moves, or puts a unit into this arena, this unit does X dice of damage to that unit." Each Ambush can be used once per instance of a unit being deployed, moved, or put.
Armor
Armor: An isolated, static ability that means, "This unit can only be hit on a roll of 5 or more." Armor works against dice of damage and attack dice. It redefines what die roll is required to hit a unit. It doesn’t modify the die roll like Accuracy. A unit with Accuracy 1 attacking a unit with Armor hits with 4's, 5's, and 6's.
Bounty
Bounty: [bonus]: A layered ability triggered during a unit discard that means, "When another unit is discarded by damage from this unit, you gain the following when your next build step starts." Bounty triggers even if the attacking unit leaves play. Bounty works in the build zone. You will gain the bounty even if the attacking unit is sent to the discard pile. The unit can't collect a bounty on itself.
Deflect
Deflect X: A layered ability activated during the damage prevention POP that means, "Prevent X damage to this unit, and this unit may do that much damage to a unit of your choice in the same arena." Deflect creates new damage that can be done to any unit in the arena (even itself). Deflect may be deflected any number of times. Damage is applied after all prevention and deflects resolve. The damage that the unit does equals the damage it prevented. You can play each Deflect effect only once for each source of damage. Deflect as much damage as you can up to the Deflect value.
Double Strike
Double Strike: An isolated, static ability played after the attack end POP that means, "You may choose a unit that this unit can attack. This unit attacks that unit. Play only if this unit just attacked and only if it tapped for that attack." The unit must tap for the first attack, not the second. If it untaps, it may double strike again. Double Strike doesn't allow you to attack your own units.
Enhance
Enhance: [Effect]: A selective, static effect that means, "You may play the following effect by paying the additional cost." The effect states whether you play it "instead" or "also". You must declare it to get its effect.
Equip
Equip: A selective effect on Equipment activated during the build step that means, "Attach this Equipment to a unit. Play only during your build step." You can pay the Equip cost only once per turn.
Evade
Evade X: A layered ability activated during the damage prevention POP that means, "Prevent up to X damage to this unit." You can play Evade only once for each instance of damage. You don't have to use all of the Evade. You choose how much damage to Evade up to X, even if the full amount of damage or more is pending.
INSERT
INSERT: A layered, static ability that means, "When this card is in play or stacked under the unit, the unit gets the following effect:" Insert works while in the build zone. The effect works while anywhere in the unit's stack. The granted ability remains to be the ability of its type. (For example, activated abilities granted by Insert may be disrupted.) The granted effect may not work in the build zone as per the rule for the rule for that effect.
Intercept
Intercept: A selective ability activated during the attack POP that means, "If one of your other units is being attacked in the same arena, the attacking unit now attacks this unit instead." Intercept doesn't end the attack. Any number of units may intercept an attack once for each instance of the effect. Each intercepting unit has been attacked. Intercept isn’t a prevention ability. Intercept doesn’t cause a new attack. (It is the same attack.) Your unit may intercept an attack from one of your own units (but not from itself) as long as that unit can attack it. If it can't attack the intercepting unit, you can pay its activation, but the defending unit won’t change. "For this attack" effects do not trigger for each intercept. Some effects may end because they don't apply to the new defending unit unless the effect's conditions are met by the new defending unit. An effect that addresses the attack can't be played for each intercept, but could continue.
Lucky
Lucky X: A cumulative, static ability that means, "Each time this unit attacks or is attacked, you may re-roll up to X of this unit's attack dice or have your opponent re-roll up to X attack dice against this unit." Both players can use Lucky effects according to the rules for POP chances. Lucky is used only once after all triggered re-roll effects resolve. You can't re-roll more dice than are rolled for the attack. You may choose to roll any number of dice up to the Lucky value.
Pilot
[sub-type] Pilot: A layered, static ability written as "[sub-type] Pilot. The [sub-type] gets:… ." that means, "You may move this card onto or off of a non-Droid Space or Ground unit of the correct sub-type once during the build step. Ignore all other text on this card except its name, sub-type and health. The piloted unit can't have more than one Pilot." Treat all of a unit's Pilot abilities for a sub-type as a single Pilot ability for that sub-type. It grants abilities to that unit alone. See the "Pilots" section of the rules PDF for more info.
Precision
Precision: An isolated, static ability that means, "This unit cannot be intercepted." An attacking unit with Precision cannot have the target of its attack changed by a unit with the Intercept ability. "Elude" is the former name of this keyword. Treat any unit with Elude as if it has Precision instead.
Reduced Cost
Reduced Cost X: A selective, static effect that means, "This card’s cost is X if the listed condition is met." Reduced Cost on cards refers to the build cost, except for Battle cards, where it refers to the Force activation cost. For this keyword, the conditional statement will always start with "If" for clarity. The condition must be met in order for you to be able to pay the "Reduced Cost."
Shields
Shields X: A cumulative, static ability that means, "The attacking unit gets –X power against this unit." Shields only matters when attack dice are rolled. If you give a unit Shields after your opponent has rolled for damage, it doesn't affect the roll.
Stack
Stack: [List]: A layered, static ability that means "You may put a listed card under this unit as part of its stack." The listed cards can't be on top of the stack. Cards with the Stack ability don't count as the cards listed and don't contest with any of the listed cards. If a card is listed by its name you can't stack a card with a different name unless it satisfies a different criteria in the [list] or they represent the same unit. (See the "Different Versions with Different Names" section in the rules PDF) Unlike a normal stack, you can only have one version of each unique unit from the [list] in the stack. Non-unique cards listed on a card with the Stack ability are permitted to form a part of the stack and you can have multiple cards with the same name in the stack as long as they are non-unique. Cards added to a card's stack using the Stack ability cannot exceed the 4 card maximum normal stacking rule. If a unique card with the Stack ability has another version of itself move to the top of it's stack, discard any cards in the stack that can't stack with the new version on top of the stack.
Stealth
Stealth: An isolated, static ability that means, "This unit can't be attacked unless it's tapped or has damage counters on it." An untapped and undamaged unit with Stealth can still be affected by alternative types of damage. (Such as Overkill.) As long as the unit has any number of damage counters on it, it can't use Stealth.
Stun
Stun X: A cumulative ability triggered during the damage placement POP that means, "When this unit damages another unit, that unit gets –X power until end of battle." If no damage counters are placed as a result of damage, Stun doesn't occur. Stun works anytime the unit damages another unit, not just when it attacks. Only the unit with both Deflect and Stun abilities can stun when it activates its Deflect.
Upkeep
Upkeep: [Cost]: A layered ability triggered when the build step starts that means, "When the build step starts each turn, you must pay the following cost." You must choose one of the costs that you can pay each turn, and ignore the others. You must still pay the Upkeep costs of a unit even if that unit is in the build zone, becomes the top card of a unique unit stack, or Pilots another unit. The Upkeep must be paid if you can pay it. If you can't pay any of the listed costs in full, then ignore Upkeep. If a unit has multiple Upkeep abilities, fulfilling just one of the Upkeep abilities (such as tapping the unit) does not satisfy all the Upkeep costs at once; it would only satisfy that instance of Upkeep. You may choose the order of multiple Upkeep abilities to keep an Upkeep from being paid, though a different order might pay it.