I have started running D&D 5e just now, so I do not have an encyclopedic knowledge of character creation options. We played a first session, with half character generation and half low-key play.
One player made a tiefling warlock and said they use their augury ability that they have since they are a tiefling. I did not carefully go through their character sheets; players are responsible for that, but I also checked some obvious sources and only found that tieflings get thaumaturgy from their race, not augury. But maybe there is some variant that gets augury, or gets to add augury to their spell list, etc. The character is first level.
The player claimed to know the rules but made false claims about them during the session. The player is a stranger to me and the other players. I will, for sure, ask them to show their work at the beginning of the next session, but I would also like to know what the rules actually say.
Is it possible for a warlock tiefling to have access to the augury spell, as a first level character?
I am most interested in official published (not Unearthed Arcana) WotC material, but if there is notable UA or well-known third party material that allows this, that would also be useful information.
(I do not, at the moment, need advice on handling the social situation, and will ask a separate question if it becomes relevant.)
Best Answer
Such a character can't cast augury, barring some kind of magic item or homebrew
Augury is a 2nd-level spell. It is not a tiefling racial spell, as you noted, nor even a warlock spell.
The Sword Coast Adventurer's Guide and Mordenkainen's Tome of Foes add a number of other tiefling variants with different racial spells - but none of them get augury as a racial spell, and those racial spells all match the template (spell level and corresponding character level) of the PHB tiefling. (The same is true of the variants originally proposed in UA: That Old Black Magic and UA: Fiendish Options.)
There are a number of published warlock patrons across the official 5e books, but none grant augury as an option from the subclass expanded spell list, and even if they did, they wouldn't add a 2nd-level spell as an option for the character to learn until the character could cast 2nd-level spells.
If the player claims to know/have access to the spell, ask them where they got it from. I see no means for any 1st-level character to do so without a magic item or some kind of homebrew.