In the past couple weeks, there's been a lot of discussion about the Pity mechanic that applies to some NPCs in the game. I'm gonna break down exactly how it works here, to hopefully clear up any confusion.

NPC Pity is a hidden mechanic in the game that increases the chances of some NPCs appearing during runs if you have not seen that particular NPC in the past few runs. This mechanic is probably intended to help with bad luck for casual players, and story pacing, but we can abuse it for speed

NPC Pity applies to: Artemis, Heracles, Icarus, Athena (naturally spawned on olympus), Arachne's story room, and Narcissus' story room

It never applies to any other scenario like nemesis, or arachne egg rooms, it only applies to those six

Also for absolute clarity, the term 'Pity' is not something used in the game code, its just what people have been calling this mechanic

Pity works slightly differently for each NPC, I'm gonna go into full detail on Artemis, and then for the rest of the NPCs, im just gonna list what's different for them. Also, all chances I give here are going to be approximate, because chances change throughout a run depending on what happens

Artemis

If you did not see Artemis in any of the three runs prior to your current run, Artemis gets an increased chance to appear

This increased chance does not bypass any of her normal requirements (e.g. non-menu room) so it only applies to rooms where she already had a chance of appearing

These improved chances are:

• Erebus: 1/18 (5.5%) -> 5/22 (23%),
  

• Oceanus: 1/17 (5.9%) -> 13/29 (45%),
  

• Ephyra: 1/12 (8.3%) -> 3/14 (21%)
  

Heracles

Gets increased chances if you did not see him in any of the three runs prior to your current run

Also, note that in thessaly, heracles can only appear in the 'intro encounter' of a ship, and in olympus he only appears in indoor rooms

Chances:

• Ephyra: 1/12 (8.3%) -> 3/14 (21%),
  

• Thessaly: 1/15 (6.6%) -> 3/17 (18%),
  

• Olympus: 1/3 (33%) -> 1/3 (unchanged),
  

Icarus

Gets increased chances if you did not see him in any of the three runs prior to your current run

In thessaly can only appear in 'reward encounters' on regular ships, in olympus can only appear in outdoor rooms

Chances:

• Thessaly: 1/11 (9%) -> 5/15 (33%),
  

• Olympus: 1/19 (5.2%) -> 1/19 (unchanged),
  

Athena

Gets increased chances if you saw her two or fewer times in the three runs prior to your current run

Chance:

• Olympus: 1/14 (7.1%) -> 5/19 (26%),
  

Arachne and Narcissus' story rooms

These work slightly differently from the NPCs that appear during combat encounters (its actually an entirely different mechanic from the pity system, but the results are similar so they belong in this discussion)

Rather than increasing the chances of these rooms appearing, these rooms get "forced" to appear if they have not been entered in recent runs

Forcing is way to complicated to fully explain here, but it doesn't override other requirements for that room to appear. If a room is 'forced' to appear in a biome, but through some insanely bad luck, you never meet it's requirements for the whole biome, it won't appear.

This is the same mechanic that causes the miniboss and midshop to appear near the middle of most biomes, it's not a complete guarantee, but it usually works.

So when I say that these rooms are "forced," I mean that they have like a 95% chance to appear

• Arachne's room gets forced if you did not enter it in either of the two runs prior to your current run,
• Narcissus' room gets forced if you did not enter it in any of the five runs prior to your current run,

Do you actually want NPC Pity?

When setting up a file to use AoAF, you can do several runs in order to enable/disable pity for each NPC by avoiding/encountering them, so which should you do?

The answer to that is very complicated, is probably different for each npc. The best general answer I can give is "it depends"

Having Pity enabled for a given NPC greatly increases your chances of seeing them, which improves run consistency. However in the ideal scenario, you want NPCs to appear late in the biome to skip a longer encounter. Having Pity enabled gives you a higher chance of running into them earlier in a biome, making it impossible to see them later in the biome; but this is possibly balanced out by the scenario of not seeing them early in the biome, and then having the increased chances from Pity late in the biome when they're most valuable

My best guesses (and these are guesses, it's hard to calculate this stuff) for whether you want pity for each NPC in an any-fear speedrunning context are:

• Artemis (underworld): no idea. This is definitely the most complicated one, I'll try to do some math and get back to you.,
• Artemis (Surface): Enable Pity. She's only possible in non-menu rooms in ephyra, and you're probably only taking one of those. You absolutely want those increased chances.,
• Heracles: probably Disable Pity. Heracles saves a small amount of time in ephyra, loses time in thessaly, and saves a lot of time in olympus. Disabling pity for him gives you better chances of reaching olympus without seeing him first.,
• Icarus: probably Enable Pity. It would probably be better to see him in olympus than thessaly, but with pity disabled you're too likely to just not see him at all,
• Athena: Disable Pity. Natural Athena spawns are always a time loss because she increases the amount of enemies in an encounter. This increased enemy thing doesn't apply to gorgon amulet.,
• Arachne: Disable Pity. You're already fairly likely to see Arachne, and her room being forced can interfere with the midshop being forced,
• Narcissus: Disable Pity. Same reasoning as Arachne.