I suspect that this might be better asked as a "explain me the perpetual damage machine" with an answer by myself saying it does not work... feel free to put on hold if you think so too and I will reopen this in a couple days.
One infamous theoretical optimization trick has a character get dealt infinite damage while under the effect of spells, feats and/or class features that keep him alive and able to take actions, in order to get benefits based on the amount of damage taken.
The infinite damage loop, postulated by LordofProcrastination and used in both "the Omniscifier" and "Pun-Pun" builds, goes like this:
- The character manifests the share pain psionic power four times, on four separate targets.
- Then, by using the glory of the martyr spell from PGtF or BoED, take half the damage dealt to these guys, restarting the cycle.
I don't think this works for two reasons.
- The text of share pain clearly talks about transferring damage.
[...] the subject takes the remainder. The amount of damage not taken by you is taken by the subject.
It looks to me that there's some sort of "conservation of damage" law implied in the wording, and that it would not be possible to redirect the same half damage you're not taking to four different targets at the same time.
- The cycle just counts totals. You get dealt 8 damage. Even if we envision that 4 damage is dealt to each of the targets of share pain, each gives back 2 damage to the "main" character. This means that 8 damage generate 8 damage and the cycle continues forever. But I would rather say that each damage is counted separately and now share pain deals 1 damage, four times, to each one of the targets, and favor of the martyr halves that damage rounding it down, and the cycle ends.
Am I correct in saying that, RAW, the theoretical optimization trick known as "Dirty Trick #2: The Perpetual Damage Machine" does not work at all, way before involving any "drowning bug" to gain your infinte negative HP back ?