This article may contain outdated information that is inaccurate for the current version of the game. It was last updated for 3.0.

Characters who are Immortal will never die from old age or disease. However, it is still possible for them to be executed or killed by events.

Characters can gain immortality with The Reaper's Due and supernatural events enabled.

When a character becomes immortal, they cease to age. The age at which they became immortal is forever their effective age for portraits, attraction opinion, fertility, and marriage acceptance. They are immune to naturally becoming infirm or incapable .

However, immortality has its downsides.

When the character grows older, they may be afraid of death and want to seek a everlasting life. The trigger requires that the character is adult, capable, not in prison and not inaccessible. The basic MTTH for the event is 3000, this probability increases as character gets older (after 50 years old), or is unhealthy.

PC can then summon council. Based on character's stat (except stewardship stat), the character can choose which council member to send. For example if your diplomacy skill is above 12, you can send your chancellor for the quest of immortality. The stat you chose here will be important in future event chain, so it is better to choose the councilor that corresponds to your highest stat. The character can also choose to (or only able to if all stats are under 12) let council make their own decision, where there is only a 35% or 15% chance that the mystic appears and a random stat is used.

Later the sent councilor will ask the character for money. The success rate of the search is basically 50:50. It increases to 100:50 with 'affordable payment', up to 200:50 with 'expensive option'. If, unfortunately, the sent councilor died or left, there is only a 35% (50% if the sent councilor failed) chance that the mystic appears and a random stat is used.

When the councilor succeeds, he brings up the mystic, a female character with the chosen stat at a very high level. For example, if you chose your chancellor for the quest, a Norse woman "Iduun" with very high diplomacy appears in your court.

The story of the following event chain, the benefits in the middle of the chain, and the risk of failure varies on which kind of mystic the character met.

There is a probability that this mystic might be a fraud, and a fraudulent mystic (almost always) fails the quest. Probability of success decreases in each step, and drops dramatically at the very last step of the quest, more than 1000:1 of failure at the very end. It is reasonably impossible to make it successful with a fraudulent mystic. The chance that the mystic is fraudulent is reduced if the chosen attribute is high (the thresholds are 10, 13, 16, 19 and 22).

When the mystic arrives and you decide to trust her, your dynasty member might be suspicious of her and try to figure out whether she's reliable or not. This is a very important step, as you can figure out whether the mystic is a fraud or not. If the dynasty member has any of the traits Deceitful , Ambitious or Envious , he will always lie to you. Meaning that if he has one of these traits, and the mystic is a fraud, he will tell you that you can trust her, and vice versa.

By using the console, you can see if the mystic is a fraud or not by using the "charinfo" command and mousing over the mystic. If she has the "mystic_is_fraud" flag, she is a fraud.

By this time, you can make sure if you should trust her or not, but even if you know she's a fraud, you can still undertake the questthe quest chain may give you a good trait, and you can abandon the chain any time you want.

As the event chain goes on, the character will encounter three events. Each event has a chance to fail, which will increase if the mystic is a fraud (see above for detail). The chance of success increases if character's chosen attribute is high (the thresholds are 13, 16, 19 and 22). Failure in an event means the end of the quest, and may result in some negative traits or even death.

In each step, the character must decide to do something (or quit), and usually spend money to have a better chance of success.

If the character's chosen attribute is martial or learning, then, in the third step, following the mystic's instructions has a chance of "succeeding" via reincarnation, which means the character will die and a child with identical race, culture, religion and some of the same traits will born as the character's child.

Dragatus shares information about the effect of stats and roughly how to tell an impostor from a real mystic: immortal-learning-path 2017 May 3rd

------ Full Quest Path Including Stat Modifiers

First thing to keep in mind before ANYTHING, is that there's about a 90% chance the mystic is a fraud when showing up which makes it 1000% more likely (the actual multiplier in the game files) that you fail the quest on the final trial and causes every single step of the trial to have an almost doubled chance of failure. So from the immediate beginning of the event you should be aware you are almost ensured failure, so pursue immortality at your own risk. Assuming the mystic isn't a fraud and you beat the first trial of luck and have a legitimate Mystic, we move on...

When the council is summoned, whichever councilor you have search for a mystic is the corresponding attribute that is going to be important. Each trial you get a bonus to succeeding the higher your stat is up to having the attribute at 22 (anything higher doesn't increase the bonuses) Thus having:Marshall finds Mystic that uses MartialCouncilor finds Mystic that uses DiplomacySpymaster finds Mystic that uses IntrigueCourt Chaplain/Imam/etc. finds Mystic that uses LearningThere is no Mystic that uses Stewardship

Once the requisite mystic is summoned, each trial generally falls under two choices that progress to the next stage, and one that backs out. There's a generally a choice that has a higher chance of success but also comes with a chance of critical failure, which can give you negative traits or immediate death. And there tends to be a choice where you have a lower chance of success but failure tends to have only negative traits given and the mystic leaves.

For a bare-bones breakdown here:

Child (Learning Mystic)

TRIAL 1:Option 1 Give CharityHas:-Kind-Drunkard-Charitable-JustSUCCEEDDoes NOT Have: If Has AND has one NOT have (20%)-Cruel-Arbitrary-Cynical

TRIAL 2Option 1 Cheat Fast-Increasing percentile of 35 maxing at Learning 22 bonuses start at Learning 13Option 2 Fast-Increasing percentile of 50 maxing at Learning 22 bonuses start at Learning 13-15% Chance of Horrible Failure

TRIAL 3Option 1-Increasing percentile of 40 maxing at Learning 22 bonuses start at Learning 13-Failure reincarnates soul into relative, copies your traitsOption 2-Increasing percentile of 25 maxing at Learning 22 bonuses start at Learning 13-Failure has you possessed

African (Martial Mystic?)

TRIAL 1Option 1 Sacrifice Antelope-Increasing percentile of 60 maxing at Martial 22 bonuses start at 13Option 2 Burn Grain-Increasing percentile of 50 maxing at Martial 22 bonuses start at 13

TRIAL 2Option 1 Grab Snake-Increasing percentile of 50 maxing at Martial 22 bonuses start at 13Option 2 Hit Snake-Increasing percentile of 35 maxing at Martial 22 bonuses start at 13

TRIAL 3Option 1 Drink Herbs-Increasing percentile of 40 maxing at Martial 22 bonuses start at 13Option 2 Ascend on your own-Increasing percentile of 25 maxing at Martial 22 bonuses start at 13

Old Crone (Intrigue Mystic)

TRIAL 1Option 1 Have her teach you-Increasing percentile of 60 maxing at Intrigue 22 bonuses start at 13Option 2 do it yourself-Increasing percentile of 50 maxing at Intrigue 22 bonuses start at 13

TRIAL 2Option 1-Increasing percentile of 35 maxing at Intrigue 22 bonuses start at 13Option 2-Increasing percentile of 50 maxing at Intrigue 22 bonuses start at 13-15% Chance of Horrible Failure

TRIAL 3Option 1-Increasing percentile of 40 maxing at Intrigue 22 bonuses start at 13Option 2-Increasing percentile of 25 maxing at Intrigue 22 bonuses start at 13

Young Germanic (Diplomacy Mystic)

TRIAL 1Option 1 Hire Adventurers-Increasing percentile of 60 maxing at Diplomacy 22 bonuses start at 13Option 2 Get Local Adventurers-Increasing percentile of 50 maxing at Diplomacy 22 bonuses start at 13

TRIAL 2Option 1 Safe Route Around Rocks-Increasing percentile of 35 maxing at Diplomacy 22 bonuses start at 13Option 2 Go Through Rocks-Increasing percentile of 50 maxing at Diplomacy 22 bonuses start at 13-15% chance of Horrible Failure

TRIAL 3Option 1 Bribe your friend-Increasing percentile of 40 maxing at Diplomacy 22 bonuses start at 13Option 2 Persuade your friend-Increasing percentile of 20 maxing at Diplomacy 22 bonuses start at 13

source: Reddit

Excerpt from:
Immortality - Crusader Kings II Wiki