Turn-Based Strategy is a strategy game where gameplay alternates between players: each player has the time to contemplate their next move and execute it, before relinquishing control to the next player. TBS games derive from traditional board games, tabletop wargames like [i]Warhammer[/i] and [i]BattleTech[/i], and the miniature tabletop battles used by real generals and historians to practice and conduct actual wars for millennia. Many computer TBS titles use similar grid maps, hit and damage systems, and unit balance concepts to their earlier dice-and-paper equivalents. TBS is known for the scale of its action, which often includes a large map for its gameplay and can vary from international conflicts all the way up to controlling whole worlds or galaxies. Larger-scale games often devolve from violent conflict into general competitive empire-building simulations with the possibility for non-violent victory, at which point they become so-called "4X" (eXplore, eXpand, eXploit, eXterminate) or “Grand Strategy” games.