A unique weapon incorporates a modification from group 1 exclusively, an epic weapon encompasses two modifications: one from group 1 and one from group 2, and a legendary weapon features a modification from each of the three groups.

Please note that only one modification from each group can be applied to a single item at any given time. Attempting to add a modification from a group where one is already present on the item will result in the replacement of the existing one.

Group 1

000FF442 - Anti-Personnel: +10% damage against humans.
000FEA07 - Bashing: Deals double damage when gun bashing.
000F437E - Berserker: Does more damage the less armor one has.
000F428E - Cornered: Damage increases as health decreases.
001625EB - Disassembler: +20% damage against robots.
000FFA3B - Extended Magazine: Doubles the base magazine capacity.
0015DD18 - Exterminator: +30% damage against aliens.
000EA117 - Furious: Each consecutive hit deals more damage.
000F2013 - Instigating: Deals double damage to targets with full health.
000FAEAB - Oxygenated: Hold-breath time when aiming using a scoped weapon is increased.
000F7321 - Space-Adept: +30% damage while in space, and -15% damage while on a planet.

Group 2

0008AB47 - Corrosive: Randomly deals corrosive damage and reduces the targets’ armor over 6 seconds.
000F2E39 - Crippling: Deals +30% damage on the next attack after hitting a target’s limbs.
000EA0BA - Handloading: Volatile rounds that are designed to pack a bigger punch, but aren’t as stable and can fail on occasion.
00122F1C - Hitman: +15% damage while aiming.
0007D728 - Incendiary: Randomly deals incendiary damage.
000FEA49 - Lacerate: Randomly applies a bleed effect to the target.
000FFA3C - Med Theft: Chance that humans drop extra Med Packs on death.
00319AEC - Poison: Randomly deals poison damage and slows the target.
000EA13B - Radioactive: Randomly deals radioactive damage and demoralizes the target.
000FEA04 - Rapid: +25% increase in attack speed.
000E8D64 - Staggering: Small chance to stagger enemies.

Group 3

000FBD3C - Concussive: Small chance to knock down targets.
000FC884 - Demoralizing: Small chance to demoralize a target.
0031C0C5 - Elemental: Randomly deals Corrosive, Radiation, Poison, and Incendiary damage.
000FA8D6 - Explosive: Randomly switches to explosive rounds.
000FC8A4 - Frenzy: Small chance to frenzy a target.
000F4CF0 - One Inch Punch: Rounds fire in a shotgun-like spread.
000F4557 - Shattering: Break through even the strongest armor.
0031C0C4 - Skip Shot: Every fourth shot fires two projectiles at once.
0031C0C6 - Tesla: Rounds will sometimes emit electricity where they land which damages and slows nearby targets.
000FFA3D - Titanium Build: Premium build materials make this weapon light as a feather.

You have the option to use the console for the addition or removal of these modifications from an item in your possession.

To begin, place an item on the ground, subsequently activate the console, and select the item to retrieve its in-world ID code. If the displayed code does not match the header WEAP, scroll your mousewheel until the entry begins with WEAP.

Next, input one of the following commands using the 8-digit alphanumeric ID code for the item and the 8-digit alphanumeric ID code for the modification (please note that the square brackets in the example command are for clarity and should not be included in the actual command):

Add/replace a mod [ID code].amod [ID of mod]

Remove a mod [ID code].rmod [ID of mod]

Posted for my personal reference copied from KnightShadePrime‘s post on reddit