How do I interpret these rules for Drugs and Addiction?

Question

One of the PCs is addicted to Aether. I have read the rules about Drugs and Addiction but I do not understand everything yet.

The rules for Moderate Addiction state:

Type disease, variable; Save variable
Onset 1 day; Frequency 1/day
Effect –2 penalty to Con and Str, target cannot naturally heal ability damage caused by the drug that caused this addiction; Cure 3 consecutive saves

The rules for Aether are:

Type drug (inhaled); Addiction moderate, Fortitude DC 16
Price 20 gp
Effect 1 hour; +1 caster level
Effect 1d4 hours; user must make a caster check to cast spells, DC 15 + spell level
Damage 1d2 Con damage

Let us say the guy is addicted and takes Aether in the morning.

• What negative effect will he have for what time? Is it -2 Con and Str for 1 day (because the Frequency is 1/day) and -1d2 Con for the first hour after he inhaled the drug?
• And how often does he have to take the drug if he is addicted?

Answer 1

As soon as the drug effects wear off or in 24 hours

This is described under the Addiction topic on Drugs & Addiction rules:

While a character is benefiting from the effects of the drug he is addicted to, he does not suffer the penalties of his addiction disease. While he still receives the benefits of the drug and takes ability damage as normal, the disease's effects are mitigated. As soon as the drug's benefits expire, the disease's effects return.

And on Curing Addiction:

Unlike with other diseases, an addicted character can only make a Fortitude save to overcome his addiction after a day of not taking the drug he is addicted to.

Then it follows the normal rules for diseases, applying the effects on a failed save based on the onset and frequency properties of the drug. For most drugs, that means one Fortitude check per day.

Once the drug effects wear off, the character is fine for a day if he passes his initial save, after that, he must make daily Fortitude saves or suffer the effects of his addiction. If he fails his initial save, he suffers the addiction effects immediatelly.

If your character has a Moderate Addiction and fails a saving thrown after the effects of an Aether wears off, you take a -2 penalty on Strength and Constitution and unable to heal the Constitution damage caused by using Aether. And this can only be prevented by taking another dose of the drug.