Hit points: in Call of Cthulhu 7e, how is your HP Max increased?

Recently I'm starting to play Call of Cthulhu 7e, and I'm really enjoying it. My researcher is also enjoying it, so, this Guardian is happy. However, we just finished our first Scenario and she asked me a question that I can not seem to answer:

How do you increase the HP Max to survive more fights? Are you simply increasing your CON or SIZ? I'm pretty sure the rules say you can only increase skills, not features, right?

call of cthulhu 7e – Mythos ability increases with the complete study of a volume

The rules of the 7th edition of Call of Cthulhu give two values ​​of skill increase of mythos for each myth: CMI (initial reading) and CMF (complete study). The general principle is clear: you get a little knowledge of a basic version of the book, and much more of a deep immersion in the horrible content it contains. What is not clear when reading the rules is whether the CMI value is contained inside (that is, it is a subset of) the CMF value.

For example, suppose a volume has CMI +5 and CMF +12. Jim flips through the book and gets +5 on his Mythos skill. When you complete a complete study, do you get another 12 full points of myth skill (for a total increase of +17)? Or earn 7 additional points? total points earned from that book to +12)?

call of cthulhu 7e – Do I understand that the rule of becoming a believer is correct?

This is all according to the English rules of "Becoming a Believer" on page 179 of the 7th edition of the Call of Cthulhu rule book:

If the character chooses not to believe what was read, then the knowledge of Cthulhu Mythos granted by the book is added to the investigator's skill and the maximum Sanity points are reduced by the corresponding amount, but no points of Sanity are lost. […] However, by finding evidence of the Mythos first-hand, the researcher will realize that those cursed books contained the truth. At that point, the researcher becomes a believer and immediately loses points of sanity equal to his Cthulhu Mythos score.

If Harvey-the-Unbeliever reads Cultes des Ghouls, he will gain + 4% of Cthulhu Mythos and have a maximum sanity of 95. If he reads the Latin Necronomicon (2d10 SAN, + 5 / + 11% of Cthulhu Mythos), he has a Cthulhu Mythos of 9% and 90 Sanity of 90. If he later found a Byakhee and lost 3 Sanity, he would immediately lose another 9 for a total of 12, leaving him in 78 Sanity of 90.

Whether being a believer or not a believer is "optimal" may not be at the point of the Call of Cthulhu, but it should be noted that sanity may be lost for reasons unrelated to Mythos, such as gruesome corpses, the violent death of a good Friend , or being confronted with a phobia, it would be very rare for anyone, except a newly created researcher, to have complete sanity. Also, it is likely that an unbeliever can go longer without preventing Sanity from seeing Mythos creatures, since it would be easier for them to pass their Sanity controls.

call of cthulhu 7e – Do the sanity loss limit rules apply to see corpses?

Do the loss of sanity limit rules apply to seeing corpses?

The rules for the loss of sanity establish that once an investigator has suffered the maximum loss of sanity for seeing a creature myths, any other loss is voided. For example, if they see a ghoul (loss of sanity 1 / 1d6) and lose 4 points, any other ghouls found can only result in 2 more points of loss of sanity. Once the maximum loss is reached, the investigator will not suffer more loss when seeing the ghouls.

So, does the same limit apply to other sources of loss of sanity? If they see a corpse and they take the maximum loss of 3 points, then they run into a garbage truck full of corpses, will they suffer more loss of sanity? Or do they build the same resistance to the loss of sanity described for mythical creatures?

call of cthulhu 7e – Limit of loss of sanity to see a corpse

Do the loss of sanity limit rules apply to seeing corpses?

The rules for the loss of sanity establish that once an investigator has suffered the maximum loss of sanity for seeing a creature myths, any other loss is voided. For example, if they see a ghoul (loss of sanity 1 / 1d6) and lose 4 points, any other ghouls found can only result in 2 more points of loss of sanity. Once the maximum loss is reached, the investigator will not suffer more loss when seeing the ghouls.

So, does the same limit apply to other sources of loss of sanity? If they see a corpse and they take the maximum loss of 3 points, then they run into a garbage truck full of corpses, will they suffer more loss of sanity? Or do they build the same resistance to the loss of sanity described for mythical creatures?

call of cthulhu 7e – Does damage to an attribute heals naturally?

Some attacks or spells can damage an Investigator's attribute score.

For example, in the module. Dead light, the titular creature has an attack:

Consume (fight maneuver): If it succeeds, it melts into its victim. The victim suffers 1D10 + 5 NO damage per turn until he dies, dying in agony as a deadly light pulses from within his flesh and boils from his eyes and mouth, and his flesh begins to burn and turns to ash. Light consumption of a victim is 1 / 1D6 of loss).

If the investigator survives in some way to this attack, will they ever recover the lost NOC from this horrible assault?