Lifespan

Each monster has a lifespan which determines how long it will live. Stress, fatigue, tournaments, and the progression of time lower your monster’s remaining lifespan.

When your monster starts a week with its lifespan at 0, they will die.

Monsters tend to live between 3 years and 5 years of age, but that will vary based on the monster’s main and sub-breeds as well as how you raise them. Rasing your monster poorly can greatly decrease their lifespan, while raising them effectively can make them live even longer.

Monsters that are frozen in the Studio do not decrease in lifespan.

Cleo’s warning

Cleo will warn you when your monster’s lifespan drops below 25% of its starting lifespan.

Um, <PLAYER>? This isn’t easy for me…

But maybe it’s time to let <MONSTER> go.

It’s starting to slow down, and…I think it’s just getting too old.

The best thing to do would be freeze and combine it at the Lab.

Even when you get this warning, you still have quite a bit of time left with your monster. Depending on your monster’s starting lifespan and how you raise them, they may have many months or even longer than a year left to live.

Strategy

To make better use of your monster’s lifespan, you can:

• Send them on drills as opposed to training in order to raise their stats

• Keep their stress and fatigue low

• Avoid letting them lose tournaments

• Feed them Tofu frequently

Factors

There are several things that impact your monster’s lifespan:

• Time passing causes your monster’s lifespan to decrease based on its stress and fatigue

• Going on drills and errantry impacts lifespan slightly differently than normal time passing

• Participating in tournaments decreases your monster’s lifespan

• Certain items can increase or decrease your monster’s lifespan

Weekly decrease

At the start of every week, your current monster’s lifespan decreases by a base amount of 10. Their lifespan is then further decreased based on the monster’s current stress and fatigue.

Stress	Lifespan	Comment
0 to 299	0	feels great
300 to 499	-2	looks a little stressed
500 to 699	-6	looks pretty stressed
700 to 899	-14	is way stressed out
900 to 999	-22	is way stressed out

Fatigue	Lifespan	Comment
0 to 299	0	feels great
300 to 499	-2	seems a little tired
500 to 699	-6	is exhausted
700 to 899	-14	it’s about to keel over
900 to 999	-22	is gonna pass out

So for example, if your monster has a stress level of 50 and a fatigue level of 350 then your monster’s lifespan will decrease by 12 (10 + 0 + 2).

In the worst case, your monster’s lifespan can decrease by as much as 52 in a single week (with 900+ stress and 900+ fatigue).

Drills & errantry

When you send your monster on a drill or errantry, while the activity takes 4 weeks, only 2 weeks worth of weekly lifespan decreases are applied. The 2 decreases are applied based on your monster’s stress and fatigue after coming back from the drill or errantry.

Because of this, doing a drill or errantry can be a more effective use of lifespan than normal training.

For example, if you monster returns from a drill with 408 stress and 436 fatigue then its lifespan will be decreased by 28. This is less than the decrease of 40 that could occur if resting or training for 4 weeks.

Tournaments

Having your monster participate in a tournament reduces its lifespan. Losing a tournament decreases your monster’s lifespan by 24, while winning a tournament only reduces their lifespan by 8.

Your monster’s stress and fatigue do not have any impact on how much lifespan they lose due to participating in tournaments.

Items

There are several consumable items that impact your monster’s lifespan. They are grouped into the following categories:

• Items that decrease lifespan as a tradeoff for temporary battle stat or training effectiveness increases

• Items that increase lifespan as a main or secondary effect

Decrease

Name	Type	Stats	Lifespan
Soybean Flour	Battle+	Power & Intelligence	-30
Dragon Scale	Battle+	Defense & Life	-25
Hot Lozenge	Battle+	Skill & Speed	-25
Spook Bug	Training+	Power & Intelligence	-30
Red Mango	Training+	Defense & Life	-25
Bell Flower	Training+	Skill & Speed	-25

Increase

There are two rare items that increase your monster’s lifespan: Silver Peach and Gold Peach. There is no limit to how many peaches a monster can eat. Lifespan only maxes out at 9999, so increasing your monsters lifespan can have it exceed it’s starting lifespan.

Name	Lifespan
Silver Peach	+250
Gold Peach	+500

Feeding your monster Tofu increases its lifespan by 5. Feeding your monster tofu every month can result in your monster living ~12% longer. [3]

Name	Lifespan
Tofu	+5

Starting lifespan

Each monster species starts out with a particular lifespan when it is created. Their starting lifespan will vary based on their main-breed and sub-breed.

The pattern for the lifespan of a given breed depending on its sub-breed appears to be the following:

• For sub-breeds that are not “?”, the monster’s starting lifespan is 60/40 the starting lifespans of the pure-breed versions of the main and sub-breeds. [1] [2]

• For “-ish” monsters, their starting lifespan is 105% of the pure-breed.

• For special “?” monsters, their starting lifespan is 90% of the pure-breed.

Below are some examples of how to calculate starting lifespans:

• Falco / Abyss has a lifespan of 0.6 * 1900 + 0.4 * 2050 = 1140 + 820 = 1960

• Falco / ? (-ish) has a lifespan of 1900 * 1.05 = 1995

• Falco / ? (Jock) has a lifespan of 1900 * 0.90 = 1710

As a further example, the table below shows the lifespans of the 7 types of Falco in comparison to their sub-breeds.

Breeds	Main	Sub	Lifespan
Falco / Falco	1900	1900	1900
Falco / Abyss	1900	2050	1960
Falco / Ogyo	1900	2050	1960
Falco / Mew	1900	2000	1940
Falco / Piroro	1900	2200	2020
Falco / ? (-ish)	1900	-	1995
Falco / ? (Jock)	1900	-	1710

Pure-breed lifespans

Below are the starting lifespans of the pure-breed species from shortest to longest living.

Breed	Lifespan	Estimated age*
Joker	1500	3 years, 1 months
Pheonix	1500	3 years, 1 months
Gali	1700	3 years, 6 months
Naga	1750	3 years, 7 months
Monol	1800	3 years, 9 months
Dragon	1850	3 years, 10 months
Zan	1850	3 years, 10 months
Falco	1900	3 years, 11 months
Pixie	1900	3 years, 11 months
Centaur	1950	4 years, 0 months
Ducken	1950	4 years, 0 months
Suezo	1950	4 years, 0 months
Tiger	1950	4 years, 0 months
Color Pandora	2000	4 years, 2 months
Hare	2000	4 years, 2 months
Mew	2000	4 years, 2 months
Mocchi	2000	4 years, 2 months
Plant	2000	4 years, 2 months
Abyss	2050	4 years, 3 months
Beaclon	2050	4 years, 3 months
Ogyo	2050	4 years, 3 months
Baku	2100	4 years, 4 months
Durahan	2100	4 years, 4 months
Pancho	2150	4 years, 5 months
Piroro	2200	4 years, 7 months
Xenon	2250	4 years, 8 months
Golem	2300	4 years, 9 months
Hengar	2500	5 years, 2 months
Lesione	2500	5 years, 2 months

* Assumes no lifespan loss beyond weekly decrease (ex. if resting every week). Actual number of years and months of life will likely be lower by a few months.

Special cases

There are four monster species that do not follow the normal lifespan calculations:

Breed	Lifespan
Geemo	2520
XBakuBaku	2100
XPalco	2280
Woodie	1850

Footnotes

[1]

Thanks to Monster Fenrick (Taylor W) on the /r/monsterrancher chat Discord server for pointing out that the lifespan for mixed-breeds might be 60/40 the main and sub-breeds’ lifespan.

[2]

A different, but equivalent, approach to calculating mixed-breed monster lifespans is described in Penopat’s GameFAQs thread.

[3]

Assuming you raise a monster such that their lifespan decreases by 44 each month. If the monster has a starting lifespan of 1500 (ex. Joker) then tofu will increase their lifespan by ~11.4% (2y 11m -> 3y 3m). If the monster has a starting lifespan of 2500 (ex. Hengar) then tofu will increase their lifespan by ~12.3% (4y 9m -> 5y 4m).