Spell: Invent Code

You grant the targets the ability to understand a newly invented language. While those under the spell’s effects can comprehend each other’s speech, it sounds indecipherable to others. The targets can also read and write in their new language, but they cease to understand the language once the spell’s duration has ended. If the same caster targets the same group with another use of invent code, they can once again understand their previous codes while the spell is active. Translate doesn’t allow a caster to understand the language, but it does reveal that the language is magically coded. Dispel magic and other similar effects can revert written text to a random but translatable jumble of all the languages the caster of invent code knows.