Sombreros is a basic shedding and bluffing game. The main components are 25 plastic sombrero-shaped hats, each concealing a sticker in one of five colours.
At the beginning of each round, players are dealt a set of hats and three hats are placed on the table. The player in turn to play may conditionally peek at the colour of a lone hat, and must then place one of their hats on one of the three piles, calling out a colour as they do so. Stating a colour is purely psychological though, as the player is only required to match colours with the hat underneath and whatever is said is disregarded entirely when confirming this. It is also possible to pass at the cost of taking a hat from the "deck".
Another player may challenge a placement, at which point the newly placed hat and the one underneath are inspected to see if they match. In typical bluffing game fashion, whichever of the challenged and challenging player is in the wrong is penalized by having to pick up the entire pile in question, and the other continues play by beginning a replacement pile.
The goal of each round is to be the first player to get rid of all hats, at which point the other players get penalty points based on the hats they still hold. The player with the least penalty points after three rounds wins the game.
—description from the publisher game submitter