In Mass Effect 3 for the PC, PS3, and Xbox 360, unlocking weapon mods to use in multiplayer games is based on a card system. You earn points to buy card packs (or you can use real money if you’d like), open the packs, and you get to use whatever you get from those packs when you play online.
Weapon mods only come in common and uncommon form, so you really only need to purchase recruit packs to get them. Obviously you’ll find weapon mods in the veteran and spectre packs, but they won’t be nearly as cost effective if you’re only looking for weapon mods.
Unlockable Weapon Mods from Card Decks
Common Weapon Mods
Assault Rifle Magazine Upgrade
Assault Rifle Precision Scope
Assault Rifle Stability Damper
Pistol High Caliber Barrel
Pistol Scope
Shotgun Blade Attachment
Shotgun High Caliber Barrel
Shotgun Smart Choke
SMG Scope
Sniper Rifle Spare Thermal Clip
Uncommon Weapon Mods
Assault Rifle Piercing Mod
Assault Rifle Stability Damper
Pistol Melee Stun
Pistol Piercing Mod
SMG Ultralight Materials
Sniper Rifle Enhanced Scope
Sniper Rifle Extended Barrel
Shotgun Shredder Mod
Shotgun Spare Thermal Clips
