Wearing armor

[Isis Blizzrd]

Sorry, but i have this dumb question and i need it to be answered:

Is it possible to wear the celestial armor with another armor at the same time?

This question came to me when i read the armor description: "This +3 chainmail is so fine and light that it can be worn under normal clothing without betraying its presence"

So i understand that you can use another armor over it, of course, the armor check penalties would stack, but also the AC bonus, i guess

I was searching for a rule that caontradicts this, but i couldn't find it, taking me to a neutral point

[Covert Operator]

No, armor bonuses never stack. if you wear two sets of armour, you apply the higher number in every category.

[kinevon]

AC bonus would not stack, only the better one (usually) applies.

Armor/Shield Bonus: Each type of armor grants an armor bonus to AC, while shields grant a shield bonus to AC. The armor bonus from a suit of armor doesn't stack with other effects or items that grant an armor bonus. Similarly, the shield bonus from a shield doesn't stack with other effects that grant a shield bonus.

[Lincoln Hills]

Your instinct that there's a rule preventing this from working is quite correct. But that rule's not in the Armor chapter. It's the general rule for bonus types, which specifies that the only bonus types that stack with themselves are Dodge, circumstance, and 'untyped'.