Attack formations are the types of attacks that a battle can begin with. Usually they involve who gets to attack first.
- Normal formation: Characters and opponents have an equal shot at getting the first turn.
- Preemptive attack: Sometimes also called First Strike, Strike First, and Preemptive Strike. The player party gets to strike the enemy first, and the characters' ATB gauges always start filled up. In later titles the monsters would also face away from the party members, allowing physical attacks to deal double damage for one turn.
- Surprise attack: Sometimes also called Ambushed, Surprised, and Sneak attack. The enemy gets a chance to strike the party first, and the party's ATB gauges always start empty.
- Back attack: Sometimes also called Attacked from behind. This is similar to the surprise attack, however, the party is attacked from behind, and each character is in the opposite row which he or she normally is in. For example, a physical fighter in the front row would be placed in the back row.
- Side attack: In this formation, the party surrounds the enemy, with two party members lining up on each side of the battle screen (or two and one if there is a three-character party). Any party member who hits an enemy with a physical attack while its back is turned deals extra damage. Most spells that target all allies will only target allies on the same side of the battlefield. All characters' ATB gauges start filled up. During a side attack the party cannot flee the battle. Some fights, such as the Goddess in Final Fantasy VI, are always side attacks. Side Attacks only appear in Final Fantasy VI and Final Fantasy VII.
- Pincer attack: Sometimes also called Surrounded. This is similar to the side attack, however, the party is surrounded by the opponents, and all characters' ATB gauges start out empty. Any character physically struck from behind takes more damage, and spells that usually affect all opponents only affect those on one side of the battlefield. Some fights, such as the Cranes in Final Fantasy VI, are always pincer attacks. Pincer Attacks only appear in Final Fantasy VI and Final Fantasy VII although the battle against Tros in Final Fantasy X features a pincer attack formation.
- Turn-Based attack: Prominent in Final Fantasy Tactics and Final Fantasy Tactics Advance, both teams start off with a number of members and when the battle begins, the fastest unit on the field goes first and so on down the line. Faster characters usually get in more turns than slower ones. The accuracy of the attack is determined on what direction you attack the opponent from. Side and Back attacks are more accurate than ones from the front. Final Fantasy X somewhat follows this formation.
- Brave attack: In Bravely Default, it means the battle starts with an additional Brave Point.
In a normal encounter, characters begin in their normal rows and their ATB gauges begin depleted and instantly begin filling. In a preemptive strike, the ATB gauges begin filled. In a surprise attack, their ATB gauges begin empty and do not begin to charge until all enemies have attacked. If the party is attacked from behind, their Rows are reversed and their ATB gauges begin empty and will not charge immediately, as in a surprise attack. Uniquely, the second battle with Scarmiglione is always a back attack.
Not all enemies can be preempted at all; it depends on the enemies and their precoded battle formations. Also, some enemies always back attack the party unless they have the Thief's Caution ability equipped. The Ninja learns First Strike which doubles the party's chance of preemptive strike from 32/256 to 64/256. If the party is back attacked, they can use the Return spell to start the battle over, usually without the back attack.
A random battle's attack formation depends on which types are allowed in the area the battle takes place. If any character is equipped with an Alarm Earring, pincer and back attacks are disabled. As in Final Fantasy V, not all monster formations can be battled in all attack formations; most formations allow all types, some disable surrounded attacks, and a few disable other types. Most boss battles disable all but normal attacks, while some other battles will always result in a surrounded or back attack.
Surrounded and back attacks will never be a preemptive strike. For a normal attack there is a 1/8 chance of a preemptive strike. Side attacks have a 7/32 chance of being a preemptive strike. If any character is equipped with a Gale Hairpin the chances are doubled. Certain monster formations (mostly bosses) disable preemptive strikes altogether.
Due to the pincer attack glitch the row command still works in surrounded attacks, even if the battles have no rows. Another surrounded attack glitch has single enemy "surrounding" the party in a surrounded attack which should not be possible.
The Tyrannosaur enemy can back attack even with an Alarm Earring equipped, and a fight with two Tyrannosaurs always results in a surrounded attack, Alarm Earring or not.
Each area has a set number of possible battle formations during a random encounter, and even for some boss battles. When a random encounter is about to start the game performs a check to see if any of the "special attack formations" apply. There is a base chance of 16/256 of getting a preemptive battle, but a mastered Pre-Emptive Materia boosts this up to 64/256. The maximum is 85/256, roughly a 1/3 chance.
If the area has any special formation battles (Back Attack, Side Attack and Pincer Attack) the chance of getting them is calculated first. These battles have the player at a disadvantage, but a mastered Pre-Emptive Materia helps protect against these battles by halving the chances of the disadvantageous ones. The game uses two types of check to detect whether or not a party member has a mastered Pre-Emptive Materia equipped: a single character check and a global check. The single character check is made whenever the player changes Materia or Equipment.
If the character does not have a mastered Pre-Emptive Materia the game will remove the "Ambush Alert" bonus, which halves the chance of Back and Pincer Attacks, and it doesn't matter if another character does actually have a mastered Pre-Emptive equipped. The global check is used when entering the menu or exiting the PHS screen by running the single character check on each character in the party in turn, starting from the top. What this means is that only the bottommost character in the party counts for whether they have a mastered Pre-Emptive Materia equipped.
After the game has ascertained whether the player gets the Ambush Alert bonus or not, and a random battle is about to begin, it will go through the four possible special formation battles for the area in the following order:
The game first checks for the Back Attack formations. It's impossible to get a preemptive attack with these battles, but the Ambush Alert reduces the chance of Back Attacks by half. The next check is for the Side Attack, where the enemy is in the middle and the player characters on the sides. The final possible battle is a Pincer Attack where the player characters are surrounded by enemies. Ambush Alert reduces the chance of Pincer Attacks by half. The game rolls a random number between 0 and 63 to determine if a special formation battle occurs and which of the special battles it is.
The way encounters are decided on the world map are slightly different: instead of a single random value being used for all four types of special attack formations, they are checked individually. This means the chance of not getting a special attack formation on the world map is not the sum of the chances, but instead the three chances of not getting a Back Attack, not getting a Side Attack and not getting a Pincer Attack multiplied together.
When the party is being back attacked the characters are normally facing away from the enemies, unless they are equipped with the Sprint Shoes, in which case the character never faces away at the start of battle. Characters facing away from enemies don't take double damage when attacked from behind, however, so the effect is merely cosmetic. By pressing and , as if trying to escape, will also immediately reverse the characters' direction at a back attack.
Some boss battles can be fought as preemptive battles if they have been flagged as "preemptive attack is possible, escape is impossible and the battle finishes with a victory fanfare". However, the only screens that allow a preemptive attack are those where random battles can be encountered. That's why the player can never preempt Rufus, for example, because no random encounters can be fought in the screen he is fought, even if the battle itself enables preemptive.
Likewise, if random battles are temporarily disabled on a screen, the player will never get a preemptive attack for any battles until random battles are enabled. As such, the only boss battles that can have a preemptive attack are Aps in the Midgar sewers, Jenova∙BIRTH in Cargo Ship, Turks:Reno with Turks:Rude in Gongaga, Snow in the Great Glacier cave, and Reno, Rude and Elena in Midgar winding tunnel. Watch a video of it here.
In a few special battles that are not back attacks, some of the back attack rules still apply: the Change command to change row is greyed out, the enemies start with an empty ATB gauge and one's first physical attack will deal double damage. This happens in the battles fought as Yuffie in the Wutai Village pagoda, and Cloud's final showdown against Sephiroth.
The battle with Ruby Weapon will always start as if the party has been back-attacked. Although no back attack message will appear, the party starts with an empty ATB gauge and Ruby Weapon gets a double physical damage bonus until it is successfully attacked.
Cait Sith's Slots Limit Break has two outcomes that usually end the battle: Death Joker and Game Over. Death Joker usually kills all allies, and Game Over usually kills all enemies. If the battle is a Side or Pincer attack, however, the attacks can only target one enemy or ally party.
The player can guard against back attacks with Cerberus's Alert ability, although it does not protect against fixed encounters, such as the second fixed Ruby Dragon battle at Deep Sea Research Center before fighting Bahamut. The Initiative ability allows the unit to begin battle at full ATB bar, but there is no ability to increase the rate of preemptive strike.
Without the Initiative ability, there is a 12.5% chance of being Ambushed, and a 12.5% chance of getting a Preemptive strike. With Initiative, there is a 25% chance of Preemptive strike and all Ambushes are eliminated (except certain enemy encounters), as long as the character with Initiative is in the active party. The player can use the First Strike ability to always get a turn first, even while being ambushed. This is especially useful because characters can be swapped during battle.
There are some enemy encounters that will always ambush the party regardless of equipment. Only three enemies are capable of this: the Great Malboro (Omega Ruins and Monster Arena only), the Malboro Menace and the first battle against Dark Yojimbo.
In Final Fantasy XIII the player can preempt the enemies, but the enemies cannot ambush the party. The player can begin the battle with a preemptive strike by engaging an enemy in battle before the exclamation mark appears above them. If the enemy is already engaged in battle with another enemy and they don't detect the party, the enemies will concentrate on each other until one side is dead before attacking the player party. However, if the enemies detect the player before the start of the battle, both enemy parties tend to concentrate on attacking the player party.
When a preemptive strike takes place, the player party starts with full ATB bars, and all enemies start with almost full Stagger gauges. The player can use a Deceptisol to make themselves invisible to enemies, and thus always preemptive them, with the oretoise and ochu enemies as exceptions.
Unlike Final Fantasy XIII the leader and the other playable character will attack the surprised enemies in a preemptive strike with a wide slash, where in the previous game, only the party leader would attack. A preemptive strike is performed using a new gameplay element called Mog Clock and gives the party Haste. Similarly to the preceding game, these battles begin with full ATB gauges but the stagger gauge only fills up to 120.0%.
Starting a battle with preemptive 50 times earns the player the Quick Draw achievement/trophy, and if the player gets 100 consecutive preemptive strikes with the Mog Clock, they earn the Clock Stopper achievement/trophy.
Enemies appear on the field and the player can strike at the foes as long as they haven't depleted their action meter by sprinting for too long. If the player strikes at an enemy from the front, they start the battle at "Good" battle condition with the enemy starting with 10% of their HP already lost. If the player strikes at an enemy from behind, the enemy starts with 25% of their HP already lost. If the player comes into contact with an enemy without striking them with their weapon, they are considered to have been ambushed, and start the battle with 5% of their HP lost.
Random battles engaged on the world map can start as ambushes or as first strikes, in the addition of normal engagements. If the party pre-emptives the enemies the opponents either start with a disadvantage—such as with Killsight on them, dying in one hit if one is fast to hit them—or the player party begins with a random buff. If the enemies ambush the party, the opponents start with an advantage, such as the Rage status, or the party starts in a disadvantage, such as in the Killsight or Stop status. If the option to replay the battle against higher level enemies comes up, the attack formation from the first battle does not carry over.
Random battles in Final Fantasy Legend III has a chance of starting with either a Strike First or an Unexpected Attack. It should be noted that boss battles can also start a battle with an Unexpected Attack. Strike First and Unexpected Attack are governed by the party's average level versus the enemy's average level. If the party's average level is higher, First Strike will occur more frequently. But if the party's average level is lower, Unexpected Attack will occur more frequently.