Mods

Modifications (Mods) are cards that can be equipped to warframes, weapons, and sentinels to enhance damage, power, survivability, speed, precepts, and utility. Mods can grant Passive Powers, Active Powers, 1/day Powers, Sentinel Precepts, and Utilities. Mods can be changed between items.

For a visual guide to mods, see this video

Obtaining mods
Mods are collected in a few ways:
 * Purchasing frames, weapons, and sentinels with platinum will give a few mods. A Warframe comes with its 4 Power Mods. A Sentinel comes with 2 Precepts.
 * Dispatching enemies. It has now been confirmed that the higher level the enemy, the rarer the mod that they can drop. Though, higher level enemies do not have a higher drop rate. Mods are always dropped as level 0 mods. The type of mod will appear in the right center of the screen when a mod is picked up. sometimes, they will be cores (see fusion energy, below).
 * Ever since the 7.7 Update, Common Mods will now drop at a high percentile, Uncommon mods with drop at a lower percentile and Rare Mods will drop at an extremely low percentile.
 * Each faction has a higher chance to drop certain mods, while having a small chance to drop other mods as well. The following is what each faction drops most often.
 * Infested: Power Abilities, All types of Freeze damage.
 * Corpus: Fire/Electricity/Armor Pen. Mods, Power Max, Power Efficiency, Power Range, Melee Charge Speed, Loot Radar and Enemy Radar, Puncture Mods. (Tactic Polarity: the line-shaped symbol)
 * Grineer: Critical Hit Chance, Critical Hit Damage, Multishot, Basic Damage Mods, Power Duration, Power Strength. (Attack Polarity: the V-shaped symbol)
 * Universal: Fusion Cores, Sentinel Mods, and Stun.
 * Raid/Spy/Capture missions offer a mod upon completion normally being Stamina Regen, Stamina Max, Vitality, Sprint Speed or a Ammo/Magazine/Reload mod.
 * Every 5 waves of defense missions will offer you a reward if you decide to exit. The rewards are random each time but tend to offer rarer mods the higher the wave you get to. With the new 7.7 Update, Defense missions have become the main source of Rare Mods.
 * Purchasing “booster packs” from the market.

Attributes
Mods have 6 attributes: (place on card)
 * Type: What the mod can be attached to. (Top left of description)
 * Rarity: How often a mod is dropped. (Top right of description and color of border)
 * Power cost: How much power a mod consumes from equipment. (Center right)
 * Polarity: Adjusts power cost of mods. (Top right of card)
 * Level: Mod strength. (Border, Center Left and with Rarity)
 * Slot: Every mod requires one slot.

Type
Mods can only be attached to their indicated type of item. They may be generally applicable to weapons, frames, or sentinels (i.e. “Warframe Mod”) or specific to their respective class (i.e. “Trinity Mod”). The type is listed in the top left of the description of the mod.

Mod Rarity
Mods vary in rarity as indicated by the border color and denoted in the description. Obtaining rarer mods from enemies requires fighting higher level enemies (needs confirmation, so far no matter the level, enemies seem to have the same chance to drop rare or common mods)
 * Bronze = common
 * Silver = uncommon
 * Gold = rare

Mod Power Cost
Warframes, sentinels, and weapons have “Mod Energy.” This reflects the items ability to maintain mods while in use. Warframes and sentinels have 10 slots for mods. Weapons and sentinel weapons have 8 slots. Without an Orokin reactor or catalyst, they can all handle 1 energy worth of mods per level (with a maximum of 30 energy at level 30). Supercharged items (with reactor/catalyst) can handle 2 energy per level (with a maximum 60 energy at level 30).

Polarity
Most slots generally accept any mod. However, some slots are “polarized.” Polarities include: Attack, Defense, Tactic, Power, and Precept. Each has a unique associated symbol. Likewise, some mods are polarized as noted in the top right corner of the card with the type of polarization. When inserting mods into slots, placing them in like polarized slots will reduce the energy cost of attaching it by 50%. Placing them in non-like polarization slots will increase the energy cost by 25%. Take note though, that it always rounds the energy cost up. So, when placing an odd number into a matching polarity slot, it will cost the same amount as if it were 1 rank higher.

'''The polarity symbols for each frame vary, making certain build types more efficient on certain frames. '''

There are five polarity symbols:

- Scratch (Warframe Abilities) - Commonly dropped by Infested

- D (Defensive, Health, Armor, Stamina)- Dropped by all factions

- V (Damage, Powers) - Commonly dropped by Grineer

- Bar (Misc.) - Commonly dropped by Corpus

- Y (Sentinel Abilities) - Dropped by all factions

Mod Rank
Mods have levels ranging from 0 to as high as 10 (typically 3-5; note that this means each mod has its max level +1 in total level ups). When the level of a mod is greater than zero, it is indicated by notches in the border centered vertically on the left side of the card. Higher level mods require more mod energy.

Bonus Stacking
To prevent exponential bonus stacking, players can't put duplicate mods in a single piece of equipment. For example, a given pistol can only have one Hornet Strike mod in it at a time.

For mods increasing shield, health or power, bonuses are calculated from the warframe's base value. This prevents exponential increases with the passive leveling bonuses introduced in update 7.6.

Mods increasing damage or adding special damage types don't conflict with each other. Given enough mod capacity, a single weapon could have mods increasing damage and adding fire, freeze, electrical and armor piercing damage at the same time, and they would all take effect at the same time when using that weapon.

Fusion
To increase the rank of a mod, navigate to the arsenal, then to "Mods" where you will choose a mod to be upgraded and click "Fusion." Selecting other mods will now be combined with this highlighted mod to make it more powerful increase the value. The selected mods will be consumed. The fusion value of a Mod is based on how similar it is to the target Mod. The level of consumed mods affects the amount of fusion energy applied: *Fusing a duplicate = 100% (1 duplicate required to reach level 1) Since Fusing mods increases their level, the power drain of the mod is also increased. The rarity of the mod being fused or used to upgrade another greatly impacts the price. It is generally more efficient to use lower rarity mods to upgrade any rarity of mods.
 * Fusing of matching polarity = 50% (2 matching polarity Mods to reach level 1)
 * Fusing unrelated = 25% (4 unrelated Mods to reach level 1)

NOTE: the entirety of the how the system works is still being figure out, but here is a good forum topic on it:

Mod Credit Cost
To upgrade any existing mod you need credits and cores or other mods. When using cores, consider this: Example: To fuse a common core of level 3 would cost 750 to fuse. A rare core of level 5 would cost 3150. When a mod would only be the base price.
 * Common mods base price is 200, plus 150 times its level for cores.
 * Uncommon mods base price is 500, plus 300 times its level for cores.
 * Rare mods base price is 1000, plus 450 times its level for cores.

Note: Ignoring the upgrade value of each core, adding lots of low level cores would probably be very expensive and not very efficient.

Fusion Cores
Fusion cores are also collected. Fusion cores can be used to upgrade any mod. Fusion cores also look like cards. They have levels, indicated by the tick marks on the border's edge (white is current level, black is total level) and rarity, indicated at the top right of the description and border color. Applying higher level cores to mods gives more upgrade energy. Applying rarer cores to mods gives a greater amount of upgrade energy. Cores can be sold for a various amount of  credits.

The amount of energy given to a mod when a core is used to level it up varies, depending on rarity and level. The credit cost to level up a mod is based on the same criteria.

Upgrade Energy
For simplicity, these numbers are based on a mod leveling up each time it gains 24 upgrade energy. Each rank that a mod has when another mod is fused with it reduces the fusion upgrade energy gained by 1/2. This penalty stacks multiplicatively, so rank 2 mods gain 1/4, rank 3 gain 1/8, etc. Uncommons additionally gain 1/2 the energy that commons do and rares gain 1/3.

Installing Mods
To install mods on an item, drag a mod from the collection and drop it on a Mod slot. If the Mod’s drain is less or equal to the item’s remaining Mod Energy it will install and Mod Energy will be deducted. Drain can be modified by the slot type: The item now has the benefits of the Mod.
 * Matching polarity reduces drain: Slash Dash costs 2, but dropped into Power polarized slot costs only 1.
 * Conflicting polarity increases drain: Slash Dash in an Attack Slot will cost 3.

Bugs

 * When fusing cores or other mods, selecting and deselecting mods may result in less upgrade points (visualy) on the bar.
 * After selecting various rare level 10 cores to fuse, adding uncommon or common cores/mods may result in a decrease in the total upgrade points, lowering the final level even.

Warframe Mods
These are mods for warframes in general. For the warframe specific powers, see the warframe.

Sentinel Mods
Specific Sentinel mods can be found on the Sentinels Page

Lore
More info coming soon