Five dice under a plastic cup can lead to major arguments. Everyone rolls simultaneously and keeps their results hidden. You bid on how many dice of a certain face exist under all cups combined, with ones acting as wild cards.

The tension ramps up when someone calls you a liar and everyone reveals their stash. The plastic cups can be incredibly noisy on a wooden table. It is an old mechanic, but trying to deduce probabilities based on wild bluffs never gets old.