Must happen:
-This could all happen after a new camper has a nervous breakdown due to hearing that the gods are the reason why his/her life sucks (The demigod in question is an orphan who lost his/her parents to a monster attack). The counsellors have an unknowingly cruel game where they laugh about people’s reactions to finding out the gods exist. The new camper should find out and blow up on the counsellors who realize that they’ve become so jaded that they are now part of the problem.

-The demigods slowly start creating their camp. The camp can be protected by anyone that’s not an Olympian. As long as the Olympians are ignorant.
[Hestia doesn’t count. The saying that all that’s necessary for the triumph of evil is for good people to do nothing applies to her.]

-The demigods slowly start recruiting under Chiron and Mr. D noses. For instance, most counsellors can decide to stay at Camp Half-Blood and vet any new members to their camp using oaths on the Styx. Some might decide to stay in Camp Half-blood for a while so the rapidly dwindling population isn’t noticed.
[Athena doesn’t notice. This is the same woman who made a little boy blind for accidentally seeing her naked. Like it was his fault a grown-ass woman couldn’t bathe in private instead of in public. The same woman who cursed a flute and left it for anyone to pick up because of peer pressure. Her divine wisdom is useless honestly.]

- Some demigods can “join” the titan side as spies for the other side.

- Eventually, at a point, the demigods are better at finding new demigods better than the satyrs. Maybe the Athena, Hephaestus, Hermes & Hecate kids make a computer capable of locating demigods. The gods do not notice exactly but they might take on their Roman forms more often since the Roman camp will still be strong.

- The demigods must not be strong enough to deal with the gods. They should focus on helping themselves more than actually fighting the gods. Not because they aren’t strong enough (although in groups they should be strong enough to deal with them and if children of the Olympians train hard enough they can become strong enough to maim them) but because they have an instinctive fear of gods.
[The demigods can kill the gods. In the myths, Ares was beaten twice by demigods and while I didn’t agree with Percy beating Ares so early (even with his broken water powers), he proved it was possible. Plus the demigods also fight titans and giants. The only hope the gods have is to take their divine form but the demigods could train to fight without sight. Maybe magic could compensate]

Recommended (Not necessary):
- Demigods are capable of using magic through runes (or the Greek alphabet, or any magic system as long as it’s not complicated. The magic system should not be too strong. I do not want overpowered demigods).

- This can happen during any period i.e. pre-canon, canon, or post-canon.

- [NSFW] The demigods should be horny as fuck. Let’s be honest, Mr. Riordan tried to keep his work PG but we’re talking about the fucking Greek Gods. They’re huge perverts and deviants. Their children shouldn’t be different. The only difference should be that their kids understand the meaning of consent. These kids barely make it to 18, they are trapped in a camp, they are hyperactive teenagers that have the god of parties and debauchery as one of their leaders and their parents are horny Mofos and despite all their problems… they are still TEENAGERS. They should be having so much sex lol.

- If an Olympian notices, it should be an Olympian like Hermes. With how his cabin is disrespected, he might turn a blind eye if his kids steal from Olympus or him. After all, the god of thieves should appreciate a good heist.

- The demigods could get funds through online businesses (kinda like the amazon stuff that happened in The Son of Neptune).

- The demigods can make the gods swear on the Styx, their thrones, and on their godly essence to leave the new camp alone.
[It is never exactly stated what happens to gods that break oaths on the Styx but here is how I see it. The Olympians and other strong immortals have some sort of geas on them for a century or so. Minor gods fade completely. Demigods die. That’s why the demigods get the gods to thrice swear.]

- The gods might decide to be petty and send the Romans to deal with the new camp. Whoever wins is up to you although I prefer that the new camp demigods win.

- If the story takes place during canon, the resentment could start from book one. The demigods would be annoyed that the gods were petty enough to start WWIII for such a stupid reason. In book 2, the demigods could be annoyed at the fact that the gods left them with a criminal as a camp director and no protection especially when nature or healing gods could have easily healed the tree.

- Some female campers could do business with Circe, Medea, or the Amazons