Polarity

Most equipment slots accept any type of Mod. However, some slots are “polarized.” Each type of Polarity has a unique symbol. Polarities include:


 * Madurai - V (Damage, Powers) - Commonly dropped by Grineer
 * Vazarin - D (Defensive, Health, Armor) - Dropped by all factions
 * Naramon - Dash/Bar (Misc.) - Commonly dropped by Corpus
 * Zenurik - Scratch (Warframe Augments and Channeling Mods)
 * Penjaga - Y (Sentinel/Kubrow Abilities) - Dropped by all factions (Kubrow from Feral Kubrows/Drahks)
 * Koneksi - O (Fusion Core) - Dropped by all factions
 * Unairu - R - Introduced in and used for certain Melee Stance Mods.

A mod's polarity type is noted in the top right corner of its card. When a mod is placed into a matching polarity slot, the cost of installing the mod will be reduced by 50%. In contrast, placing a mod in a slot with a different polarity will increase its cost by 25%. This cost is rounded to the closest integer.

For Aura and Stance mods, polarities increase or decrease the amount of bonus mod points that the mod provides: matching polarities will increase the bonus mod points by 100%, while non-matching polarities reduce it by 20%.

A Warframe's polarity slots differ from the slots of other Warframes. This makes certain mod builds more efficient on certain frames.

Polarization
Players may use Forma, a rare item obtainable from Orokin Void missions or the Market, to add or change a polarity on a piece of equipment that has attained rank 30. This increases the weapon or frame's overall strength by increasing the possible mod combinations that may be placed on it. Using Forma to add/change a polarity slot will reset the equipment's rank to zero, requiring the equipment to be leveled up again. Additionally, polarization allows players to rearrange polarity slots as they see fit, including polarities that were built into the equipment to begin with. As of, the aura slot's polarity cannot be swapped with another slot's.

Currently, there appears to be no cap on the number of times a weapon may be 'polarized' or what polarizations are possible (on a weapon with eight blank slots, you could polarize it eight times with the same polarity if you so wish) though good judgement on how you wish to build a weapon undoubtedly means variety will serve most Tenno well.