Conditional Turn-Based Battle

The Conditional Turn-Based Battle system (often abbreviated to CTB) is a battle system used in Final Fantasy X, Final Fantasy Tactics and Final Fantasy Tactics Advance. The system was designed by Toshiro Tsuchida.

At its most basic, Conditional Turn-Based Battle is a turn-based system which does not operate in rounds, so although each character's turn is atomic, the order of the turns does not guarantee that each participant in a battle has an equal number of turns. Characters with higher Speed can have more turns than slower characters. Furthermore, spells and abilities can modify the turn order (called the Act List), as some abilities require a longer cool down time. In general, weaker abilities tend to require less cool down time, thus introducing a trade-off between speed and power.

The system is distinguished from the Active Time Battle system by the fact that when a character's turn begins, all action stops while the player decides upon an action. This shifts the focus from reflexes and quick decision-making to strategy and careful planning.

Final Fantasy X has an augmented CTB system, allowing the player to substitute characters while in the middle of a battle (the "party interchange system".)

Related appearances
Similar battle systems have been seen in games by other publishers, such as Electronic Arts' . Such other systems are not actually known as CTB systems, however, as that name refers explicitly to Square Enix's implementation. Furthermore, the details of the system are not constant across the three games in which it has been implemented.

 has a battle system reminiscent of the CTB system (although the CTB scale, showing the order of turns, is often incorrectly referred to as an ATB scale). The latest game to include the CTB system is Lost Odyssey. It is also worth noting that this game was designed by Hironobu Sakaguchi, widely considered as the father of the Final Fantasy game series.