Uncle Screwie can be played with as little as 2 players, or 3 players, or as a partners game, where there is an even number of players, like 4. Groups of six play all the time. You could play eight but at that point, we’d recommend two tables of four.
When playing with 2 or 3, you would just be playing as an individual against your other opponent or 2 opponents.
Strategy is the same, just no partner to work off of, but equally fun!