Brabble is a simple but interesting word game that includes bluffing, based on traditional student word games.
The players consecutively add letters (from a small selection) to one of three frames, creating words that include the framed letters in the same order...or do they? Because you can add a letter without knowing a word that actually contains the created fragment. As long as the next player doesn't challenge the fragment, you are safe. Players score a point for successfully adding the last letter that fits into a frame and for winning a challenge.
The challenge: Choose one of the frames and ask the previous player to name a word that contains the respective fragment (in the exact order of the letters). If they can, they win a point; if not, you do.
The game ends in a "best of three", which means that whoever scores the second point wins.