Riven mods are a special kind of mods that can only be equipped in a specific weapon but it comes with some extra powerful stats compared to normal mods.
When you first acquire a Riven mod, its stats are veiled - you need to complete a random challenge before you can actually use the Riven mod. Some of these challenges are easy if you know what to do, other challenges may require several tries but it is fun and in most cases rewarding to do so.
After the challenge has been completed, you can now see which Weapon the Riven is compatible with and if you are lucky the Riven will fit one of your favorite weapons and also have great stats. However, it is much more likely that the Riven will either fit some weapon you rarely use or have some crappy stats. For example, when I first leveled my Boar Prime I didn't really like it but after getting a good Riven it is now one of my preferred weapons against high level enemies.
After the Riven is unveiled the weapon and polarity is locked and can not be changed but you may try to reroll the stats if you are not satisfied. Each reroll will cost an increasing amount of Kuva. If you are lucky you may get some nice stats in first try or you may use large amounts of Kuva and still not get what you want. It is all up to RNG - good luck Tenno!
For more information on how to unlock Riven mods by doing Riven Challenges, see this guide.
Example of veiled Riven with a random challenge
Same Riven after unveiling - sadly this one has great stats but for a weapon I do not like that much...
Where do you get Riven mods from?
Riven mods can be acquired from the daily Sortie mission or as a special Gift From The Lotus mission after a DevStream has been streamed on Twitch - check the News panel in your orbiter for when next DevStream is coming up!
If the stats on the Riven mod is not what you wanted, you may use Kuva to roll for other random stats - however you can not change which weapon it is compatible with. For each roll it becomes more and more costly to change stats (up to an upper limit). You can farm Kuva from the daily Sortie, at the endless Kuva Survival mission on Kuva Fortress or by doing the Kuva Siphon missions on the two planets closest to the Kuva Fortress. Check out this guide for more info on how to farm Kuva.
How do you reroll the stats on your Riven?
In order to reroll a Riven you first need to farm some Kuva from:
- Mission reward from daily Sortie
- Kuva Survival mission on Kuva Fortress
- Kuva Flood or Kuva Siphon missions on planets near Kuva Fortress
- Reward from Nightwave Intermission
Once you have plenty of Kuva, go to the Mods terminal on your Orbiter ship, select the Riven you want to cycle and click the Cycle action. Then click the Cycle for... button to cycle the stats on the Riven to some new random stats. If the new stats are better, click the Confirm button - if you prefer your previous stats just click on the Riven to the left and click Confirm to keep your previous stats.
Start by selecting a Riven and click the Cycle Action.
Click the Cycle button and then confirm you want to cycle this Riven.
Select either the Riven on the left to keep your previous stats or the Riven to the right to accept the new stats.