Riven mods in Warframe: where they come from, challenges, kuva and disposition

What a riven mod is

A riven mod is a mod for one specific weapon with random stats: two or three positive attributes and sometimes one negative. Two rivens for the same weapon almost never match, which is why a good riven can be worth more than the weapon itself.

A riven opens in three stages. At first it is unrevealed: you only see the weapon type, rifle or melee for example. Equip it on a weapon of that type and it becomes veiled and shows a challenge. Complete the challenge and it unveils: you see which weapon it is for and its stats.

Where riven mods come from

• Sorties. A riven is one of the possible daily Sortie rewards.
• Nightwave. Some seasons include a riven among the rank rewards.
• Palladino. Twice a week she turns 10 Riven Slivers into a riven.
• The War Within quest. Gives one riven for free on completion.
• Players. Veiled and unveiled rivens sell on warframe.market.

The challenge: how to unveil a riven

A challenge is a task plus a condition. The task says what to do: kill so many enemies, finish a mission. The condition adds how: without taking damage, while invisible, in a particular place. You complete one challenge once and the riven unveils.

Some task and condition pairs are easy in any mission, others need planning. The riven mods page has a helper: pick the task and the condition and it puts together a note on how to combine them.

Kuva and rerolling

An unveiled riven can be rerolled: pay kuva and get a new set of random stats. Each reroll of the same riven costs more than the last.

• The first reroll costs 900 kuva, and it climbs from there.
• The cap is 3,500 kuva per reroll; it never goes higher.
• The reroll count shows on the mod and transfers to the new owner with it.

Because of that last point, a riven with many rerolls usually sells for less: every attempt the next owner makes costs the maximum straight away. The full cost table by step is on the riven mods page. Kuva itself is farmed in kuva missions and the Kuva Fortress.

Disposition: why some weapons love rivens

Disposition is the multiplier on a riven's strength for a given weapon, from 0.5 to 1.55. The game shows it as one to five dots. The higher the disposition, the bigger the numbers on the mod.

• High disposition usually belongs to weak or rarely used weapons: the game strengthens rivens for things few people play.
• Low belongs to popular weapons that rivens already make strong.
• It changes roughly every three months, with each new Prime Access. Rivens that are already unveiled are recalculated automatically.

The current disposition of every weapon is on the riven mods page.

Sell it veiled or unveil it

A veiled riven sells like a lottery ticket: the buyer pays for the chance it turns out to be for a weapon whose rivens are expensive. An unveiled riven sells for its actual stats.

• Sell veiled if the challenge is hard and veiled rivens of that type are fetching a good price right now.
• Unveil if the challenge is easy: an unveiled riven for a popular weapon with good stats is worth noticeably more.
• Don't reroll for resale on an unpopular weapon: the kuva is gone and the buyers do not multiply.

Trading a riven needs Mastery Rank 8 to 16 depending on the mod, and the trade tax is 8,000 credits.