@Gamasutra Felipe Pepe shares his opinion on the art of turn-based battles in RPGs.

The Art of Turn-Based RPGs I: Menu-based battles

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Action Order:

Ok, so the game is Turn-Based... but who goes first? Well, it depends.

In traditional Turn-Based games, each character has a turn. Turn order is usually decided by initiative/speed, and sometimes a very fast character can have more turns than a slow one. You can see this in games like Final Fantasy X, Temple of Elemental Evil, Fallout 1 & 2, the Gold Box games, etc.

Some games - especially tactical ones such as X-COM, Disgaea or Jagged Alliance 2 - instead alternate between a "player turn", where you control all characters and attack, followed by an "enemy turn", were the opposing force does the same. This elevates the risk & reward: you can coordinate your attacks and deal a lot of damage, but then you'll have to endure the enemy doing the same.

However, a few RPGs use instead a Phase-Based system (aka "We-Go"), where you and your opponent give orders to all characters and then the actions are executed all at once.

This is a more chaotic system, that requires some gambles. Let's say you are facing a strong monster and one that is near-death: how many characters should attack the near-death one? Just one? But what if the attack misses? Several? But if the first attack kills, then the others might be wasted...

Initiative is also key. If one of your characters is dying, a fast monster might kill him/her before your slow Cleric can cast a healing spell - will you take the gamble, or order the Ninja to use a healing item?

This system was used mostly on older RPGs, such a Bard's Tale and Wizardry, but lives on in modern Wizardry clones, such as Etrian Odissey, Stranger Of Sword City or Elminage: Gothic.

In 1991 Final Fantasy IV introduced the ATB (Active Time Battle) system, where characters can act as soon as their ATB bars fill up. This remains the quintessential JRPG combat system for a lot of people - especially since it was used in several of Squaresoft JRPGs in the 90s, including FFVII:

Final Fantasy X-2 expanded upon the concept, adding bonus damage when the player chains attacks together. Final Fantasy XIII added more flexibility: you could quickly execute weaker attacks, or wait for it to charge further and unleash stronger ones - a useful choice when trying to keep a combo up:

Bravely Default elevated combat turns into a resource. Characters can skip turn to save them for later, attacking several times at once or using powerful attacks that take several turns to execute. They can also spend more turns than they saved, which will force them to helplessly stand still for a few turns.

Grandia, on the other hand, made the turn order itself interactive - characters "race" each other on a timeline to select an action. Each action takes a certain time to be executed, and you can try to interrupt an enemy's attack, delay it or quickly prepare a defense before it lands. This system was later used in games like Penny Arcade's On the Rain-Slick Precipice of Darkness 3 & 4 and Child of Light:

Nowadays many gamers are familiar with the Persona series, where hitting an enemy with elemental magic he's weak to will negate his turn and leave him exposed. But the Turn Press system in the Shin Megami Tensei games goes much deeper. During your turn you get a certain number of points to use - and each action will consume some of those points.

However, Critical hits or exploiting enemies' weakness consumes less points than normal, while a miss will consume more points. And if you screw up big - like using a spell the enemy can absorb, you lose ALL points and your turn will end.

It's an elaborate system, that requires you to know each enemy and their weakness, then exploit those to make your turn last as long as possible.

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