Companions

Companions are loyal personal allies to the Tenno. They will use their own unique precepts, weapons and abilities to assist their owners in their missions at any cost, even going so far as going directly into harms way to protect them. Companions are not a one-time-use ally gear like Specters, but rather equipped in their own slot in the user's loadout via the arsenal. Users can only equip one companion at any time. A companion's stats, abilities, and behaviors can be upgraded and manipulated via their own set of mods. Modding companions is similar to modding Warframes.

There are currently three classes of companions: robotic Sentinels, and living Kubrow and Kavats. There are many differences between these classes ranging from combat and movement behaviors to acquisition to possible maintenance requirements.

Sentinels


Sentinels are hovering companions which use range weapons. Sentinels are revived in missions when either their owner revives or a Regen mod activates. Sentinels require no maintenance.

Kubrows


Kubrows are terrain-restricted melee canine companions. Reviving Kubrow in missions is similar to reviving allied Tenno. Kubrows require constant care and maintenance, but are more durable than sentinels. They also have different races, breeds, color palettes, and color patterns.

Kavats
Kavats are terrain-restricted melee feline companions similar to Kubrows. Reviving Kavats in missions is similar to reviving allied Tenno. Kavats require constant care and maintenance, but are more durable than sentinels. They also have different races, breeds, color palettes, and color patterns.

Precept mods
In general, precepts are mods which alter the behavior of a companion. Think of them as the companion's "abilities". Every type of Sentinel and Kubrow has their own specific precepts that cannot be used by other type (i.e.: the Djinn Sentinel cannot use the Carrier Sentinel's Vacuum precept). However, there are precepts that are universal within a class of companions. Upon acquiring a companion, the user is automatically granted its respective specific precept mods.

Companions will use their precepts in a prioritized order, where the top left slot is the highest priority and the bottom right slot is the lowest. Precept mods do not need to be installed in the respective polarized slot to be used. Also, while the Arsenal UI only shows the first 4 precepts installed, a Companion will  still use other precepts if they are installed.

Companions will check to see if the conditions to use the highest priority precept are fulfilled, and will continue to use that precept until the conditions are no longer met. Then they will check each other precept in priority order. Companions will also interrupt the usage of lower priority precepts to use higher priority precepts.