Elemensus is a tile laying word game where the tiles are elements from the Periodic Table. The players form words using these tiles by placing them on a grid board made to represent the Orion Nebula. Players may start their words on specially marked spaces and build upon words from there. Words are scored based on the elements used in the word with the scores being that element's atomic weight. Many elements are difficult or impossible to form words with so every element has "Dark Matter" reverse side with a letter and a point penalty for using this side in a word. Bonus points can be earned by forming element names with only the element side of the tiles. Some variants are included in the game rules.