I'm getting ready to run a game that deals with death in fancy ways, and I was sincerely curious about the opinions of people on this message board.
There are 3 facets that make the campaign sincerely different from the standard campaign in the form of new Mechanics.
1 - The party of four is considered their level +1 for the purposes of CR to make the combats consistently more difficult across the board, albeit not entirely overwhelming. (Tentative, and most likely to not be made)
2 - Essence. A Player has 1 essence per odd level that they have, total. If a player ever has 0 essence, they die. A player loses 2 essence every time they die, unless their campaign quality (Their Essence Choice) says otherwise. A player takes a -1 penalty to attack rolls and saves per Essence that they're missing. Essence can be taken from dead humans, stolen from Eldritch Horrors, and robbed from Wells of Essence (Which are not common, and a terrible thing to destroy.)
3 - Eldritch Knowledge is a strange version of a haunt. You see the haunt, make a Knowledge: Planes roll, and willingly accept the effects of the haunt. Failing the save has different long-lasting effects than making the saves, and most often only apply to a single character a time. An example of the Eldritch Knowledge is seeing Bright Light as if it were perfect darkness, and vice versa.
4 - Dark Feats. Dark Feats are versions of mythic feats that can be taken after they choose a feat named "Influenced by Darkness" which lower their total Essence count. The Dark Feats are effectively Mythic feats, but use Essence as a source instead of mythic power, which comes back. Posessing a Dark Feat also lowers the amount of Essence you can have, total.
What do you think?
It seems like this would encourage evil characters far more than good aligned ones. Maybe counter balance the Dark Feats with some that rely on having a lot of essence, maybe requiring a feat called Beholden to Light, that work by increasing your maximum Essence.
That's actually a fantastic idea. There are already feats I've made that compliment people that wouldn't want to kill others, anyway. Why not reward them more for that, eh?
Glad to help out.
I should probably point out that while most of the stuff listed is good for getting Essence back in evil ways, there are actually some variables to how effective all of this is.
For stealing essence, a character has to be freshly dead. A creature must walk up to them (Creature can also mean player), and make an "Essence Check". An Essence check is a composite score of your Wisdom, Charisma, and Intelligence Modifier. Most Essence "Forms" require a DC 25, 20, or a 15. Most of those require a 20. Feats can also increase the check, and then some.
Attempting to steal Essence means you usually just want one, but you can take more than 1. Rolling a 32 on a 20 means you get 3 essence, because you overcame 20, 25, and 30. That person is also most likely very dead.
Dying usually causes you to lose 2 Essence, but very specific ones can cause you to lose only 1, or a large 3.
Killing an Eldritch Horror causes everyone pleasant to gain 1, or 2 depending on their Essence "Form." A person with the "Alien" Essence gets 2 Essence from a horror, after all. Excess Essence just dissipates, uselessly. The campaign gives plenty of gear, but it isn't rewarding with Essence at all.
Destroying a Well just maxes everyone present's Essence, and cuts the "Bond" anyone has with it, and they're immediately aware of this when it happens. If a person dies when they're not connected to a well, they stay dead.
Odd thought: corrupted essence pools. basically if someone who is linked to an essence pool that is corrupted/tainted they not only lose 2 essence like normal, but come back as something different. maybe something extra, maybe something less, or maybe just completely different.
A good example is an essence pool that turns people into vampires or one that turns people into terrible eldritch abominations. Things that good adventurers probably want destroyed, and evil adventurers MIGHT want preserved.
Couple of ideas; first, maybe allow spellcasters to "shift" Wells from one location to another through a ritual or powerful spell, but at a cost. Maybe they lose several points of Essence to relocate a Well to a new location of their choice.
Second, a weapon enchantment that lets you steal Essence on a critical hit. Maybe price it as a +2 weapon?
Last idea, allow undead that do Level Drain to drain Essence instead (or divide the drain amongst both), but have their stolen Essence be used to power them. Maybe each point of stolen Essence grants +5 temporary hit points.