Biologically immortal humans would live 600-700 years.

[Ferghis]

... at least according to the guys behind this research: Q: Does the 2nd law of thermodynamics imply that everything must eventually die, regardless of the ultimate fate of the universe? | Ask a Mathematician / Ask a Physicist

The relevant bit:

Statisticians (being weird and morbid) have figured out that if Humans were biologically immortal the average lifespan would be around 600-700 years. It takes about that long to slip in the shower or something (statistically).

At first glance, this fits with many settings' conception of biologically immortal races. However, one could adjust this lifespan if the setting were particularly violent (many are) or if medical technology was less than modern. Obviously, a lack of technology could be more than made-up for by magic.

 

[mmadsen]

However, one could adjust this lifespan if the setting were particularly violent (many are) or if medical technology was less than modern.

That's quite an understatement. Being "immortal" in a quasi-medieval setting might not mean much, unless you were also wealthy yet not committed to military service. And motherhood would be a terrible risk...

 

[Ferghis]

Quite true, especially that last point.

On the other hand, disciplined, sedentary, low-risk lifestyles are not rare in fantasy settings. Despite the fact that Rolemaster penalized their self-discipline (IIRC), Tolkien's elves remind me a lot of vulcans: cerebral and monastic creatures that aren't into risk-taking. I think these kinds of races could actually live a very long time, if they were biologically immortal.

 

[Li Shenron]

You can also explain even longer lifespans of some fantasy races with the fact that they don't shower.

 

[mmadsen]

Tolkien's elves remind me a lot of vulcans: cerebral and monastic creatures that aren't into risk-taking.

D&D doesn't reflect this well, but imagine a race of elves, all high level, but all with one hit die. How would they fight an orc horde?