are you allowed to lie if your parents tell you to do so?
for example i am 13 years old, bu when i go to an amusemnet park they tell me to say im 12 to get the discount. Is that permisssible?
Generally in such scenarios the parent will be the one lying about the child’s age. If that is the case you should not say anything as this is not the time or place for you to rebuke your parents. However for you to say an outright lie, you should respectfully decline. If met with resistance, suggest that perhaps you could ask your family Rav what the right thing to do is. I am sure you parents will be proud to see how careful you are about Torah and Mitzvos.