There are a lot of helpful video guides that come out every week showing how to do the current week’s Challenge Rift. I know they’ve helped me out many times.
So, a big Shout-out to all the Challenge Rift video uploaders out there. 
Two things, however, that occasionally get asked and I never see covered in these videos are:
- How do you start a Challenge Rift?
- How do you collect your Challenge Rift Cache?
So, that’s what I’m going to show you in this thread. (By the way, I suck at Challenge Rifts. I hope you’ll forgive me for that. 
)
What you should know:
- There’s a new Challenge Rift every Monday at 2:00 PM Pacific Time.
- You can collect your Challenge Rift with any Character you currently have. It doesn’t matter if it’s Normal, Hardcore, Season or non-Season. But, you must have a Character in that Game Mode before you start your Challenge Rift.
- As stated, Challenge Rifts change on Monday. New Seasons usually start on Friday. If you want to start your new Season with a pocketful of currency, you must wait for the Season to start first. Create your Seasonal Character or Rebirth a non-Season Character. Once you have your Seasonal Character you can run the Challenge Rift.
The following 9-minute video demonstrates starting a Challenge Rift, successfully completing it and collecting the Challenge Rift Cache. You will also see how much loot is dropped. Gold, Bounty Mats, Blood Shards and Death’s Breaths are always the same. I believe the Crafting Mats have a range, but I don’t know what that range is. But, you get no Forgotten Souls. 
Enjoy! 
D3꞉RoS Challenge Rift Cache
| Currency | Amount | |
|---|---|---|
| Gold | = | 5,100,000 |
| Bounty Mats (x5 Acts) | = | 15 |
| Blood Shards | = | 475 |
| Reusable Parts | = | ~ 370 |
| Arcane Dust | = | ~ 354 |
| Veiled Crystal | = | ~ 126 |
| Death's Breath | = | 35 |