Certain competitive sports, such as racing and gymnastics, are not games by definitions such as Crawford’s (see above) – despite the inclusion of many in the Olympic Games – because competitors do not interact with their opponents; they simply challenge each other in indirect ways.
Lawn games are outdoor games that can be played on a lawn; an area of mowed grass (or alternately, on graded soil) generally smaller than a sports field (pitch). Variations of many games that are traditionally played on a sports field are marketed as «lawn games» for home use in a front or back yard. Common lawn games include horseshoes, sholf, croquet, bocce, lawn bowls, and stake.
Most other board games combine strategy and luck factors; the game of backgammon requires players to decide the best strategic move based on the roll of two dice. Trivia games have a great deal of randomness based on the questions a person gets. German-style board games are notable for often having rather less of a luck factor than many board games.
Board game groups include race games, roll-and-move games, abstract strategy games, word games, and wargames, as well as trivia and other elements. Some board games fall into multiple groups or incorporate elements of other genres: Cranium is one popular example, where players must succeed in each of four skills: artistry, live performance, trivia, and language.
Some board games include a deck of cards as a gameplay element, normally for randomization or to keep track of game progress. Conversely, some card games such as Cribbage use a board with movers, normally to keep score. The differentiation between the two genres in such cases depends on which element of the game is foremost in its play; a board game using cards for random actions can usually use some other method of randomization, while Cribbage can just as easily be scored on paper. These elements as used are simply the traditional and easiest methods to achieve their purpose.
Variations of traditional dominoes abound: Triominoes are similar in theory but are triangular and thus have three values per tile. Similarly, a game known as Quad-Ominos uses four-sided tiles.
Some other games use tiles in place of cards; Rummikub is a variant of the Rummy card game family that uses tiles numbered in ascending rank among four colors, very similar in makeup to a 2-deck «pack» of Anglo-American playing cards. Mahjong is another game very similar to Rummy that uses a set of tiles with card-like values and art.
Lastly, some games use graphical tiles to form a board layout, on which other elements of the game are played. Settlers of Catan and Carcassonne are examples. In each, the «board» is made up of a series of tiles; in Settlers of Catan the starting layout is random but static, while in Carcassonne the game is played by «building» the board tile-by-tile. Hive, an abstract strategy game using tiles as moving pieces, has mechanical and strategic elements similar to chess, although it has no board; the pieces themselves both form the layout and can move within it.
Pencil and paper games require little or no specialized equipment other than writing materials, though some such games have been commercialized as board games (Scrabble, for instance, is based on the idea of a crossword puzzle, and tic-tac-toe sets with a boxed grid and pieces are available commercially). These games vary widely, from games centering on a design being drawn such as Pictionary and «connect-the-dots» games like sprouts, to letter and word games such as Boggle and Scattergories, to solitaire and logic puzzle games such as Sudoku and crossword puzzles.