Červii

Červii, also known as Cervii or Worms, is a Czech freeware multiplayer arcade game created by Vladimír Chvátil for MS-DOS and released in 1993. It was one of Chvátil's earliest known computer games; he later contributed to titles including Fish Fillets and Original War and became internationally successful as a designer of board games. Despite its extremely simple presentation, Červii became a popular multiplayer game in the Czech Republic and Slovakia during the 1990s.

The game supports between two and six players simultaneously, all sharing a single keyboard and playing on the same screen. Each participant controls a continuously moving and growing coloured worm, represented by a simple line on a black background. A worm cannot be stopped or accelerated, and each player has only two controls, used to turn left or right. Under the standard rules, touching the edge of the playing field, another worm or one's own trail results in elimination from the current round.

The objective is both to survive and to force opponents into collisions by gradually restricting their available space. Although the controls require only two keys, successful play depends on quick reactions, spatial awareness and the ability to anticipate the movements of other players. The game becomes increasingly chaotic when five or six people compete around the same keyboard, with the continuously expanding trails dividing the arena into progressively smaller and more dangerous areas.

Before a match, players can adjust several rules, including which types of collisions are permitted, the target score and the organization of participants into teams. Points are awarded according to the circumstances in which worms collide, and the match continues over multiple rounds until one player reaches the predetermined winning score. The game contains no computer-controlled opponents, making the presence of at least two human players essential.

Červii uses extremely basic graphics and sound and offers little variety beyond its central mechanic, but its simplicity is also the main source of its appeal. Matches begin almost immediately, the controls can be understood within seconds, and no individual player requires a separate controller. The game was consequently well suited to groups gathered around a single computer and is remembered as a notable example of early Czech freeware whose lasting popularity depended on competitive local multiplayer rather than technical sophistication.