Armor Mods

Chest armor and leg armor have boosted inventory ammo capacity, while helmets typically have grenade-boosting modifiers. Gauntlets always have a faster reload mod on them.

Less commonly, you may find mods that improve super charge times or interact with the Orbs of Light that friendly Guardians generate.

Defense Boosts

All armor also gets access to upgrades that increase the basic Defense stat of the armor piece, similar to the Attack upgrades on weapons.

Grenades

INCREASED GRENADE THROW DISTANCE

A very useful mod in both PvE and PvP, this gives your grenades some extra velocity on the throw, which can significantly increase the distance you can throw them. Remember that grenades inherit your existing momentum, so sprinting and jumping can impart extra range if you’re really going for a long bomb.

One quirk: if you do decide to use this mod, you may experience some discomfort switching between armor sets with or without it. Your grenades suddenly being thrown a different distance can completely ruin your aim until you adjust. In general, if you make heavy use of grenades and stack Discipline, this upgrade is just as important as the melee speed armor mod for melee lovers.

BONUS MELEE ENERGY ON GRENADE HIT

For grenade and melee lovers, this mod gives you 3% melee energy back every time you hit an enemy with a grenade. Note that this has an internal cooldown of six seconds, so you can’t drop a lingering grenade on a pack of adversaries and instantly fill your melee bar!

This mod is generally a bit more useful in PvE than PvP simply because of enemy density. In most cases, throwing range is more relevant in PvP (though not universally true, like on smaller maps).

Melee

REDUCED MELEE RECOVERY TIME

A vital mod for melee lovers, this mod reduces the time it takes to recover from melee swings by 25%. This makes a huge difference in PvP, and it can also be helpful in PvE if you get swarmed at close range. Note that the recovery time only affects your ability to perform another melee attack; it does not help with getting your gun ready faster after a melee swing.

BONUS GRENADE ENERGY ON MELEE HIT

A flat bonus of 6% grenade energy for a melee hit, this is a nice upgrade for a Discipline/Strength split build or a pure Discipline build where you simply want the absolute fastest possible grenade recharge.

Orbs of Light

Orb armor mods grant you bonuses when you pick up a friendly Orb of Light. This applies to any Orb of Light anywhere in the game, be it PvE, PvP, in a public space with a random player, or in a private Strike area with your Fireteam.

Orb mods are most useful if one or more players in your Fireteam are running Intellect builds. An organized group that coordinates super usage can benefit greatly from using these mods in difficult missions. These mods are generally a bit less useful if you solo often or don’t play with heavily coordinated groups. In those situations, you may find that you get more benefit from other armor upgrades.

HEALTH REGEN ON PICKUP

This mod gives you a small 10 health boost immediately and allows health regen to continue for 1.5 seconds even if you are taking damage. This is a very powerful mod with a coordinated team—you can turn idle orbs on the battlefield into emergency health restore pickups.

BONUS GRENADE ENERGY ON PICKUP

A flat 6% grenade energy boost for each orb you pick up. To get the most benefit from this mod, lob a grenade just before you dive into a pool of orbs.

BONUS MELEE ENERGY ON PICKUP

Identical to the grenade mod, this is a flat 6% melee energy boost for each orb you pick up. If you are purely melee-focused, you can add this to the grenade and melee mods to have the absolutely maximum possible number of melee boosts on your armor. Otherwise, consider using one of the other two orb mods, as they are typically more useful in a wider range of situations.

Super

GAIN SUPER ENERGY WHEN KILLING AI COMBATANTS

This boost gives you 5% more super energy on top of what you would normally get for killing any enemy during a mission. Note that this mod does not apply to opponents in PvP.

Keep a piece of this gear around for PvE, but swap it to the second grenade-specific super armor mod for PvP, or a different armor mod entirely.

GAIN SUPER ENERGY FOR KILLING ANY ENEMY WITH GRENADES

This mod gives 7% more super energy on top of the base bonus for killing any enemy with a grenade. If your build is grenade-focused, or (even better) if you’ve split between Discipline and Intellect, this is a perfect mod to add to your suite.

Weapon

FASTER RELOAD SPEED

+10 Reload.

Specific to gauntlets, this mod boosts your Reload stat with one class of weapon (typically a primary weapon on most armor). It is possible to find gauntlets that boost specific special or heavy weapons, or even ones that boost Reload for an entire weapon class rather than a specific weapon.

When configuring an entire armor and weapon loadout, keep an eye on the reload mods available for your weapons. You may or may not need the added bonus from your gauntlets, or you can shift it to a different weapon class. 

BONUS INVENTORY AMMO

Found on chest armor and leg armor, these mods grant you more backpack ammunition, ideal for lengthy and difficult missions. Similar to reload armor mods, these bonuses come in a variety of forms. You can find bonus ammo for a specific weapon, or you can more rarely find mods that boost the ammo capacity for an entire weapon class.

The amount gained varies depending on the type of weapon. For example, you get more of a bonus to a primary weapon than a rocket launcher.

Class Armor

There is one final piece of Class-specific armor: Class Armor is purely cosmetic, with one exception. Acquiring a piece of Class Armor from a specific Faction in the game allows you to represent that Faction on the battlefield. This gives you a means of earning New Monarchy, Dead Orbit, or Future War Cult reputation while you complete activities.

Keep in mind that PvE activities normally earn you Vanguard reputation, but equipping yourself with one specific Faction’s Class Armor changes your rep gain to that Faction instead.