The term I tend to prefer is "transmortality" and yes, there's even a deity in my pantheon who sponsors pursuits in that direction. Granted the goddess of the cycle of souls isn't particularly fond of him dabbling in what she considers her domain.
I suppose transhumanism in a d20 system depends on your definition of baseline humans. Maybe norms have 10 ability scores across the board and never gain any class levels whatsoever. Or maybe norms can only gain levels in NPC classes, and all PCs are transhuman sheerly by dint of their level advancement. Or maybe norms are martial classes and caster classes benefit from a sufficiently advanced tech.
I guess what I'm saying is, if anyone out there is running a game where Gandalf and Ben Kenobi start at first level and gain enough levels to face off against the Borg queen, I wholeheartedly approve!
I tended to think of 3.x dragonborn as prime examples of transmortalism. On many ways it struck me as being a still living version of the process by which souls became petitioners.Weren't they just another race?
In 3.x they were another race you chose to become, but you had to essentially quest to become one. It was a prestige race, instead if a prestige class.
Also, while I don't know where LazarX is, in the US and Canada you can't buy your way to the top of the transplant list. Arguably wealthy patients can sit higher due to better general care and the potential to be healthier for given length of time waiting and to wait longer, but that is a very different thing than buying an organ.
Why would you rely on the whims of fate in North America? If you have the money (it was around $100k a few years ago), you can go to China and buy an organ from a compatible "donor". Not from some back alley criminal, but through a government sanctioned execution of a prisoner.
Some of you might be interestec in A Gift from Earth, which has a whole society whose "justice" (actually oppression) system and organ transplant system are inextricably intertwined.
D&D/Pathfinder doesn't support this by default, though. Spells that could mimic sonething like this are high enough up the tech tree that by the time you could do that, you could (at least if divine casting) use a regular Regenerate to fix your problem without needing to take somebody else's body parts.
Immortality would be a fantastic scientific triumph, but one I suspect would lead to a societal disaster.
Mainly because humans are awful.
More specifically, the ones that are power hungry enough to become leaders of nations often are outright awful.
But no matter how bad they are and how deeply entrenched they are, death will still remove them in the end. And then things can move forward.
But if they could become immortal and remain running the show forever?
That would pretty much mean the end of any progress in those nations.
(Also, I'd expect a hard push for abolishing term limits in democracies if remaining in power forever actually came within the grasp of the establishment =P)
As far as Pathfinder goes - amusingly, most of the players in my group immediately seek immortality for their PCs if the option becomes somehow available. My own PCs usually don't.
(When GMing, my usual take is that mortals don't actually cope well with immortality, and so it often goes very badly. Non-evil ex-mortals are pretty rare. The mortal does better if they manage to transform into something that CAN cope with immortality, like an outsider.
of course, what they did to make that transformation may carry with its own problems.)
{. . .]
(When GMing, my usual take is that mortals don't actually cope well with immortality, and so it often goes very badly. Non-evil ex-mortals are pretty rare. {. . .}
My take on that is that mortals don't deal well with mortality either, and non=evil mortals are actually rather rare. Immortality would be just another tool for the elites -- they would prefer to be immortal, but in fact they manage to keep their boot heel on the throats of everyone else just fine in a revolving door system.