Not sure if it was a fluke, but at the Liar's Dice table in Escalera, there was only one player. So I only had to beat him.
As for Liar's Dice strategy, keep your bets as honest as possible. NPCs rarely call bluffs when you only wager one or two of a die face. Once they are down to their final die, they always bet on the actual last die that they have.
There's an in-depth guide here:
https://reddead.fandom.com/wiki/Liar%27s_Dice