This is the 3408th most frequent Russian word.
правилах
"Правилах" means "rules" (in the prepositional case).
The word 'правилах' is used here in its nominative plural form 'правила' to refer to regulations or guidelines.
Недавно были изменены правила.
The rules were recently changed.
Here, 'правилах' is in the prepositional plural form, indicating the subject of discussion.
Мы поговорим о новых правилах.
We will talk about the new rules.
In this sentence, 'правилах' is again in the prepositional plural form, stressing the necessity of adherence.