A turn-based strategy (TBS) game is a strategy game (usually some type of wargame, especially a strategic-level wargame) where players take turns when playing. This is distinguished from real time strategy where all players play simultaneously.
Many board games are turn based. For example, chess is one of the oldest and most competitive games of its kind. But many other games such as Reversi, checkers, Hare games and Go are also turn based.
Turn-based tactical game-play is characterized by the expectation of players to complete their tasks by using the combat forces provided to them, and usually by the provision of a realistic (or at least believable) representation of military tactics and operations. Tactical role-playing games are a part of this genre. Examples include Fire Emblem, The Battle for Wesnoth, Poxnora, Silent Storm, Steel Panthers: World at War!, King's Bounty, Great Big War Game, Nintendo Wars, UniWar, XCOM 2 and uTanks.
After a period of converting board and historic TBS games to computer games, companies began basing computer turn-based strategy games on completely original properties or concepts. The presence of a computer to calculate and arbitrate allows game complexity which is not feasible in a traditional board game.