Linguist Feat

You have studied languages and codes, gaining the following benefits:

Prerequisite: None

• Increase your Intelligence score by 1, to a maximum of 20.
• You learn three languages of your choice.
• You can ably create written ciphers. Others can't decipher a code you create unless you teach them, they succeed on an Intelligence check (DC equal to your Intelligence score + your proficiency bonus), or they use magic to decipher it.

Source: PHB'14, page 167