In Diablo Immortal, Elder Rifts combine Nephalem Rifts and Greater Rifts from Diablo 3. These are relatively short dungeons, and they’re randomly generated. Inside, it would help if you killed monsters quickly to find the Guardian, a boss that must be defeated. You will then be entitled to many rewards based on the crests used when opening the Rift.

Fault Start
As with many activities, go to the type of altar called the Ancient Rift Entrance in Westmarch after you’ve progressed far enough in the story. This feature is usually introduced after defeating the Blood Countess in the Forgotten Tower, beyond the Dark Forest.
You can perform the Fail alone or in a group. This second option is much more profitable since the peculiarity of the Ancient Rifts is the possibility of improving them using rare or even legendary Rift Crests, which will unlock rewards for all players.
Many exciting items are waiting for you inside the Rift, such as experience orbs, shrines, and a particular vendor that sometimes appears after the Guardian dies.
Crests and Rift Upgrades
These unique items can be obtained in various ways in-game, such as by completing Trial Rifts, progressing through the Battle Pass, or purchasing from the Shop. Each emblem used will add a modifier to the Rift, which can affect monsters or players and can be positive or negative. Each player in the party can use up to 3 flags in the same Rift.
Rare Crests guarantee you a Rune, while Legendary Keys guarantee you 3 Runes and a Legendary Gem. A particular currency, Fading Embers, is also distributed to the entire party based on the number of crests used in total. These serve as currency for legendary runes and gems from a particular vendor.
Without crests, the profitability of Ancient Rifts isn’t terrible, but it’s a little better to go farm other things outside or do dungeons. A good strategy is to stock up on crests and chain glitches to 4 players so everyone benefits.
Ancient Rift Modifiers
Here is an essential list of modifiers found so far. These modifiers do not interfere with the rewards gained on success. They will only determine if it will be easier or more difficult.
Positives
Skill damage increased.
Attack speed increased.
Attacks make monsters bleed.
Attacks sometimes trigger a chain of lightning.
Monsters low on health are executed.
Increased rate of Life Orb generation.
The Guardian is eliminated.
An additional treasure is offered as a reward.
Negatives
Enemy dodge increased.
Enemies sometimes explode on death.
Enemies sometimes come back to life.
Enemy attack speed is increased.