Weapon, armor, and gear qualities referenced by rating (X) throughout the Ranged Weapons, Melee Weapons, and Armor tables. Paraphrased from the core rulebook's Item Qualities section, verified directly against the scanned pages in the Core Rulebook (pp. 154-157). Passive qualities are always in effect. Active qualities must be triggered by the user — by default this costs on the check, unless a quality's own entry says otherwise.
Passive Qualities
Accurate X
Add X to combat checks made with this weapon.
Breach X
Ignores X points of the target's armor rating (and ignore 10(X) points of soak)
Cortosis
A weapon with this quality can't be affected by Sunder. Armor with this quality makes the wearer's soak immune to both Pierce and Breach.
Cumbersome X
The wielder needs Brawn ≥ X to use the weapon properly. For each point of Brawn short of X, increase the difficulty of all checks made with the weapon by one.
Defensive X
Increases the wielder's melee defense by X while wielded.
Deflection X
Increases the wearer's ranged defense by X.
Inaccurate X
Add X to combat checks made with this weapon.
Inferior
Weapons: generate automatic on checks made with the item, and reduce base damage by 1. Armor: increase encumbrance by 1 and reduce soak by 1 (or defense by 1, if it has no soak — minimum 0).
Ion
Deals damage as system strain rather than wounds/hull trauma (still reduced by soak/armor). Affects droids' strain threshold rather than wounds.
Limited Ammo X
The weapon can make X attacks before it needs reloading with a maneuver (or, for single-use items like grenades, X uses before it's expended/needs replacing).
Pierce X
Ignores X points of the target's soak (fully ignores soak if Pierce exceeds it — the excess has no further effect).
Prepare X
The wielder must perform X preparation maneuvers before attacking with this weapon.
Slow-Firing X
After firing, the weapon can't be fired again for X rounds.
Stun Damage
Deals its damage as strain instead of wounds (still reduced by soak). A related variant, Stun setting, lets the wielder switch a weapon to deal Stun damage as a free action — while set to Stun, the weapon's range is capped at Short and can't be increased.
Superior
Weapons: generate automatic on checks made with the item, and increase base damage by 1. Armor: reduce encumbrance by 1 and increase soak by 1.
Tractor X
On a hit, the target can't move unless its pilot succeeds at a Piloting check with difficulty based on the Tractor rating.
Vicious X
On a Critical Injury/hit, add X × 10 to the critical roll.
Active Qualities
Auto-fire
Using this quality increases the combat check's difficulty by one (the wielder can choose not to use it and skip this penalty). On a hit, spending scores an additional hit — this can be triggered multiple times per check — allocated to the original target or another target in range (the first hit must go to the highest-difficulty/highest-defense target if splitting). Each additional hit can also trigger its own Critical Injury at the normal cost.
Blast X
On a successful hit, spending deals X damage (+1 per additional net success) to every character — friend or foe — engaged with the original target (not the original target itself, which already took the normal hit). On a miss, spending still detonates the weapon: the original target and everyone engaged with it takes damage equal to the Blast rating.
Burn X
Triggers automatically on a successful hit — no Advantage spend needed. The target keeps suffering the weapon's base damage at the start of each of their turns for X rounds. They can attempt to stop it (as an action) with an Average Coordination check on hard ground or Easy on soft ground/grass; jumping into water stops it immediately. (This assumes an actual fire, not a chemical/energy burn — those may not be extinguishable this way.)
Concussive X
On activation (default — no override is given in this quality's own entry), the target is staggered for X rounds. A staggered target can't perform actions.
Disorient X
On activation (default 2 Advantage), the target is disoriented for X rounds. A disoriented target adds to all skill checks they make.
Ensnare X
On activation (default 2 Advantage — the entry doesn't restate a cost, unlike Knockdown below), the target is immobilized for X rounds and can't perform maneuvers. As their action, they can attempt a Hard Athletics check to break free early.
Guided X
Requires spending to activate (unless a specific weapon's entry overrides this). If the attack misses and Guided activates, the wielder can make another attack check at the end of the round: difficulty is based on comparing the weapon's silhouette (treated as 0) to the target's silhouette, rolling a number of Ability dice equal to the Guided rating. Success means the weapon still strikes and deals normal damage. "Spoofing" countermeasures (e.g. flares against a guided missile) increase the target's defense specifically against Guided attacks.
Knockdown
On a hit, spending (plus 1 more Advantage per silhouette above 1) knocks the target prone.
Linked X
On a hit, spending scores an additional hit against the same target — up to X times per check. Each additional hit deals the weapon's base damage plus total net successes on the check.
Stun X
On activation (default 2 Advantage), deals strain to the target equal to the Stun rating.
Sunder
Costs only (a single Advantage — cheaper than the usual 2) to activate. The attacker picks one item the target is openly wielding (weapon, shield, belt item, etc.) and damages it one step: undamaged → Minor → Moderate → Major → destroyed. Can be triggered more than once per attack, potentially destroying an item outright in one hit.
General framing from the rulebook: item qualities have a rating (X) that scales their effect; unless a quality's own entry says otherwise, Active qualities cost to trigger. Per an official rules clarification (not on these pages, but from FFG's Sam Stewart), a given item quality generally triggers only once per target on an attack — the stated exceptions are qualities like Auto-fire and Linked that explicitly generate extra hits, each of which can separately trigger other qualities.
Not reproduced here: "Unwieldy" shows up in several community rules-compilation sites as a melee/Agility counterpart to Cumbersome, but it does not appear anywhere in this section of the core rulebook (pp. 154-157) as scanned. Either it's from a different Star Wars RPG line/supplement, or those compilations are simply wrong — don't use it without a citation from an actual sourcebook.
Source Edge of the Empire Core Rulebook, Chapter V - Gear and Equipment (p. 154-157)