Apart from the fact that the party size has been reduced from four to three, the combat mechanics are otherwise very similar to FFVI. The trusty old Active Time Battle (ATB) system is still here: time bars indicate when a character is ready, you input a command for them, and they execute it right away. You can switch between two characters who have their time bars full by pressing Triangle, which can be handy if you need emergency healing or whatnot. However, you can’t input any commands during summoning sequences, for some reason. Otherwise, you can still choose to change rows or defend by pressing the left and right directional buttons. Front and back rows work as usual: characters in the front will deal and take full damage from physical attacks, while characters in the back will see both of those values halved. Magic and ranged attacks, on the other hand, will deal full damage from any row. Combat configurations make a return from FFVI: on top of the usual preemptive attack (the party faces the enemies’ backs for increased damage and starts with their time bars full) and back attack (the reverse), you have the side attack and the pincer attack. In the former configuration, the party surrounds the enemies and has full time bars, with the result that at least one party member will always be able to target an enemy’s back. The latter configuration is the reverse and probably the most dangerous combat situation the party can find itself in.
Aside from the time bar, additional bars have been added under a character’s HP and MP, indicating the relative amount they have left. This is redundant for HP, but it can be helpful for MP, since the combat menu only displays a character’s current MP without comparing it to their total, unlike HP. There are also two additional bars next to each character’s name, helpfully indicating the duration of Barrier (physical protection) and MBarrier (magical protection), which are both spells you can learn.
However, the blood and bones of the combat system is materia. Your characters don’t have any inherent individual abilities besides their Limit Breaks. They also don’t learn magic naturally. Instead, they rely on materia: small coloured spheres of solidified Mako which have spells and abilities ‘stored’ inside them (designated in-game as the knowledge of the Ancients) and are used to enhance weapons and armour. This is a simple, but rather inventive system, which allows for a wide range of customisation.
Each piece of weaponry and armour has a certain number of circular slots in it, which are used to fit materia and are sometimes linked. Materia comes in five varieties: green (magic), blue (support), red (summon), yellow (command) and pink (independent). Green materia includes your usual spells like Fire, Ice, Cure, etc. Red materia features the staple Shiva, Ramuh or Ifrit, along with some new stuff like the infamous, 13-hit, Knights of the Round (yes, “table” is missing). Yellow materia offers things like Steal, Throw or Enemy Skill, which is the equivalent of blue magic (i.e. magic learned from enemies). Pink materia covers stuff like Long Range (allows melee weapons to deal full damage from the back row), HP Plus, Enemy Away (reduces the random encounter rate), etc. Blue materia is used exclusively in linked slots, in conjunction with other materia, usually green or red. It includes things like All (spells are single-target, this makes them multi-targetable), Quadra Magic (allows the character to cast a spell or summon four times in a row), or Steal as Well (the character attempts to steal after casting a given spell). Every piece of materia levels up with Ability Points, or AP, that characters gain in battle alongside EXP. Its progression is designated by stars in the main menu. Not only does higher level materia allow characters to use its abilities more often–a level one Fire materia lets them cast once per fight, a level two twice, etc.–it also unlocks more spells. For example, the Heal materia allows a character to use Poisona, which cures the recipient from Poison, at level one; Esuna, which cures any status ailment, at level two; and Resist, which makes the recipient immune to status ailments (basically the spell version of a Ribbon) at level three. When a piece of materia reaches its final growth level (becomes ‘mastered’), it replicates, creating another level one copy of itself. This effectively means that, given the need and patience, your team can become a self-sufficient materia factory. Mastered materia also sells for rather hefty prices (All, in particular), so it’s also a potential source of money.
Enemy Skills are learned when a character is hit by given spells, regardless if they survive. To speed up the process, it’s a good idea to put all your Enemy Skill materia on one character while you’re learning them. It’s also worth noting that Enemy Skill materia doesn’t replicate, as it doesn’t level up, only fills up with spells.
One more thing: some materia has a direct effect on characters’ stats, raising and/or lowering them by a few points. The most dramatic instance of this are green or red materia. Put too many of those on one character and watch their HP plummet as their MP skyrockets. So use with caution, lest your designated caster get slaughtered.
You may remember the Desperation Attacks from FFVI. FFVII reuses the concept and implements it fully, establishing it as one of the staples in the series. Each character now has their own unique set of powerful attacks called Limit Breaks, monitored by a Limit bar, which is situated next to their time bar in the combat menu. As they take hits from enemies, this bar gradually fills up. When it’s full, it starts flashing wildly, the time bar fills very rapidly, and the character’s Attack command is replaced by the Limit command (i.e. the character can’t attack normally until they’ve used their Limit Break). There are four levels of Limit Breaks; each of the first three levels includes two attacks. In order to gain a new Limit level, a character must kill a certain number of enemies. To gain the second attack for that Limit level, the character must then use the first attack a set number of times. The fourth Limit level only has one attack. Those are learned from manuals you discover over the course of the game; each character has their own, except Cait Sith, who only has two Limit levels. Vincent is yet another can of worms: while his menu only lists one Limit per level, each of his forms has two different attacks.
You can choose which Limit level you want to use, regardless of how many a given character has learned: for example, if Barret has reached his second Limit level, you can still use Mindblow (a first level attack) to deplete an enemy’s MP, if needed. The difference lies in the fact that higher Limit levels, while being more powerful, require the character to take a lot more hits for the Limit bar to fill up. It’s also worth noting that Tifa can use every attack she knows up to her selected Limit level when you trigger her Limit Break (provided you align the slots correctly): so, if she has learned her first level three attack, she’ll be able to use both her level one attacks, then both her level two attacks, and finally her level three attack. Limit bars carry over from fight to fight, so if you don’t mind temporarily losing the capacity to attack normally, you can store a character’s Limit Break for a boss battle, for example. However, if the character dies, their Limit bar will instantly empty.
Last but not least, each character has an ultimate weapon, which is usually more powerful than any other weapon they can equip, but unfortunately prevents their materia from levelling. So don’t use them if you’re trying to master your materia. Alternatively, you could just put the materia you want to level on that character’s armour. Every ultimate weapon also has a specific attack formula: for example, Yuffie’s one is more powerful against stronger enemies, Vincent’s one becomes more powerful as he kills more foes, etc. Tifa’s one is absolutely dreadful though, as its power depends on how full her Limit bar is, meaning that it will be well-nigh useless if she’s just used a Limit Break.