Lifespan

A lifespan is a ledger kept on each body, holding two numbers: how many ticks of life are left and the ceiling this life was granted, both in ticks (24000 ticks is one game day) and both stored in the lifespan attachment. Every number in the ledger comes from a data pack, a command or the server config — the mod hard-codes no world-view value of its own — and the server config decides how the line runs. The whole system is off by default, so upgrading changes nothing.

Where the numbers come from

Source	When it writes
lifespan on a realm_stage	Once, on the breakthrough that reaches that stage, as an increment; a literal constant must be finite and non-negative or loading is refused.
The mxt:modify_lifespan entity action	add (negative amounts take life away) or set (rewrites both numbers at once).
The mxt:reincarnate entity action	Makes a body be reborn on the spot: it runs the very same reset list as On expiry set to reincarnate and reopens the ledger from Base lifespan (0 means not accounting for the body at all); it writes no number of its own, it only reopens the account. The details belong to the entity action types.
The command /mxt lifespan set / add / reincarnate	An administrator rewrites or adjusts it directly; reincarnate makes a body be reborn on the spot and reopens the ledger from the Base lifespan setting.
KubeJS MxtLifespan	A script reads or writes it.
Server Config → Lifespan → Base lifespan	With the master switch on and that value above 0, this is what a body is seeded with on first login, or on the first settlement of a body that holds a ledger nobody ever granted life to; it is also the starting point when add opens a brand-new ledger. Reincarnation recomputes to it too.

A body with no ledger reads as "not accounted for": the lifespan_remaining / lifespan_total formula variables read NaN and /mxt lifespan get says so outright. Writes are unaffected by the master switch, which only decides whether time passes.

How the server settles it

• One settlement every Settle interval (20 ticks by default) spends Age per settle (20 ticks by default) of life; the ratio between the two is the rate, and setting the age to 0 settles without ageing at all.
• Every entity in a level shares one settlement beat (taken modulo the level's game time), and each body spends from its own remaining ticks. The countdown runs on entity ticks, so it does not pass while offline and logging back in never back-pays.
• Creative and spectator bodies are outside settlement — spectating is what running out leaves a player as, which is also what keeps one death from being replayed.
• The moment the remaining life falls to the Warning threshold fraction (0.1 by default) of the ceiling, the action bar warns once. Only the crossing warns, not every settlement after it.
• With the master switch off, the whole line stands still: no settlement, no seeding, no expiry, no warning and no row on the character panel; turning it on resumes the ledgers from that moment and never back-pays the time it was off.

After it runs out

On expiry has three settings:

Value	What happens
death (the default)	The player is turned into a spectator: nothing drops, no death event fires and no respawn point is set, and the ledger keeps its 0 (which is not "unlimited" — grant life again and it carries on from there). A non-player creature dies of the mxt:lifespan damage type instead, whose death message key is death.attack.mxt.lifespan; that type is in the mxt:no_bonus tag, so it takes no part in bonus settlement (see The damage system).
reincarnate	The body is washed back to a mortal on the spot; what it keeps is on the Reincarnation tab below. The very same reset is also reachable on demand: the /mxt lifespan reincarnate command, MxtLifespan.reincarnate and the mxt:reincarnate data pack action run it.
none	Nothing is done at all: only the lifespanEnd event fires and content decides.

Before any of that, Pre of lifespanEnd fires and can be cancelled: a listener that writes a positive lifespan inside the event (through the service or straight onto the attachment) has extended the life and the countdown carries on, while a listener that writes nothing only refuses that one end — the account closes (remaining = -1, total = 0) instead of being retried forever. Post carries getOutcome(), naming the branch the base ran. The details are on MxtEvents.

Character Information Panel

The character information panel (Z by default) gains a Lifespan row: the remaining life and the ceiling, read as years through Ticks per year, or as ticks when that setting is 1; a body with no ledger, or one whose ledger has been closed (a negative remainder), shows "Unlimited". With the master switch off the whole row is not drawn.

Command

/mxt lifespan (with the top-level alias /lifespan, switched by Server Config → Command Aliases → /lifespan) reads and rewrites the ledger: get prints every target's ledger, set rewrites both numbers, add adjusts them (a negative amount takes life away and only lowers what is left, never the ceiling) and reincarnate makes a target be reborn on the spot (it runs the reset list on the Reincarnation tab and reopens the ledger from Base lifespan, where 0 means not accounting for the body at all). The write nodes set / add and reincarnate, and get when it names other targets, need the gamemaster permission. Each subcommand is described on /lifespan.

Server Config

Lifespan

Setting	Default	Effect
Server Config → Lifespan → Enable lifespan	off	The master switch, described under "How the server settles it" above.
Server Config → Lifespan → Base lifespan	0	The ticks granted on first login, or on the first settlement of a body that holds a ledger nobody ever granted life to; 0 disables seeding. Range 0..1000000000000.
Server Config → Lifespan → Settle interval	20	How many ticks pass between two settlements. Range 1..72000.
Server Config → Lifespan → Age per settle	20	How many ticks of life each settlement spends; its ratio to the settle interval is the rate (20/20 is normal, 20/40 half speed, 40/20 double), and 0 settles without ageing. Range 0..72000.
Server Config → Lifespan → On expiry	death	The values are death / reincarnate / none, described under "After it runs out".
Server Config → Lifespan → Warning threshold	0.1	The fraction of the ceiling at which the action bar warns once — only on the crossing; 0 turns it off, and 1 never fires either, because the remaining life is never above its own ceiling. Range 0.0..1.0.
Server Config → Lifespan → Ticks per year	24000	The divisor the character panel and the warning use to read ticks as years; 1 shows ticks. Range 1..1000000.

Reincarnation

With On expiry set to reincarnate, these switches decide what the rebirth keeps.

Setting	Default	Effect
Server Config → Reincarnation → Die first	off	On: the body goes through a real death (items drop, the death message is filled in, a respawn point is set) before it is washed back to a mortal.
Server Config → Reincarnation → Reset realm and progress	on	Clears realm stages, cultivation progress, sitting state and sitting cooldowns, so the body is a mortal again and may break through the first stage afresh; the passive attributes and minor-stage abilities those realms granted are taken back with them.
Server Config → Reincarnation → Clear minor stage records	on	Clears the record of how far the body ever got inside each realm. Left in place, content gating on a stage count would keep treating the threshold as already reached after a rebirth.
Server Config → Reincarnation → Cancel a running tribulation	on	Drops a tribulation in progress without its success or its failure action.
Server Config → Reincarnation → Clear resource values	off	Empties every resource value (each is re-initialized from its definition on the next read). The base leaves resources alone by default, because which value counts as cultivation progress is a data pack's decision.
Server Config → Reincarnation → Keep spirit roots and physiques	on	Keeps spirit roots, physiques and their enabled/disabled state; off clears them too.
Server Config → Reincarnation → Keep techniques	on	Keeps learned techniques and their progression levels — the memory stays while the foundation is rebuilt; off clears them too.
Server Config → Reincarnation → Keep the four soul values	on	Keeps karma, heart demon, soul strength and soul sense range; off returns all four to zero.

Related

• Fields: lifespan on realm_stage, mxt:modify_lifespan / mxt:reincarnate and the lifespan_remaining / lifespan_total formula variables.
• Script entry point: MxtLifespan (it reads and writes the ledger and can make a body be reborn); the callback when a life runs out: lifespanEnd in MxtEvents.
• The command: /lifespan.