An enemy is an AI-controlled opponent appearing in a battle that a player often must face and defeat. The majority of Final Fantasy games involve encounters with enemies that players defeat in battle. The term enemy is often used synonymously with monster, though not every enemy fought is a monster, especially in later titles where humans (or human-like races) and mechanical enemies become more common.
Some enemies are considered bosses. They are generally more difficult to defeat and require strategy, and either play a role in the story, prevent progression, or hold or protect items of importance.
Enemies may be associated with one or more types that describe an aspect of them. For example, common types are Undead and Flying. These types automatically add various attributes to the enemy that modify how elements, statuses, and types of damage affect the enemy. Common examples are Flying types becoming immune to ground/earth damage, and Undead types becoming weak to Holy and taking damage from restorative.
Enemies usually belong to no more than one family. Enemy families often do not dictate anything about the enemy besides their appearance, however families will share commonalities such as common abilities and types of attack. For examples, members of the Behemoth family use Meteor abilities, and members of the Goblin family use Goblin Punch.
In 2D games, families are usually identified as being palette-swaps of each other. In 3D games this is also true however differences of scale and other variations in the texture or palette are more common. Due to 3D games using animations, ability commonalities are also more common in 3D games as families usually share the same skeleton.
Enemies in the first game are typically encountered on the field in random encounters. Up to nine enemies may be faced in a single battle. For each unique location in the game, a specific subset of enemies are encountered. Enemies are also set into specific formations, which limit what enemies can appear alongside each other if a battle is triggered.
In the original release, enemies had the statistics of HP, Attack (not to be confused with Strength), Accuracy, Number of Hits, Defense, Evasion (not to be confused with Agility), Critical Rate (not to be confused with Luck), Magic Defense and Courage/Morale. Enemies also have a set amount of experience and Gil to award upon their defeat. Later remakes would add Agility, Luck and Intellect statistics, remove the critical rate statistic, and add item drops as a possible additional reward.
An enemy's regular attack can have an element associated to it along with an affliction. If a player character can resist the element of the enemy's physical attack, then they also resist having the status effect inflicted upon them.
Enemies in the game can wield magic and/or use enemy-exclusive skills. Enemies can have up to 8 unique spells and 4 unique skills. These are placed in spell list and an independent skill list. When an enemy determines to use a spell, it chooses spells in the list sequentially and loops back to the first spell by the end, creating a cycle. The process for skills is identical and separate from the spell selection.
The AI used by enemies is relatively simple. First, it determines if it attempts to escape. This is done through a calculation involving its courage or morale level against the lead party member's level. If the enemy does not try to escape, then it checks if it casts a spell, at a rate of chance unique to each individual monster. If it chooses to cast, then it uses the spell it is currently on while moving the pointer forward to the next entry in its spell list. Otherwise, the enemy determines if it uses a skill, using an identical process to magic. If it chooses to do none of these earlier things, the enemy will attack physically.
For example, take the Evil Eye enemy. On its first turn, it can choose to cast a spell, so it will cast the first spell in its list (Thundara). The second turn, it can choose to cast again, so it casts the next spell in its list (Hold). On the third turn, it can choose to use a skill. Note that because this is the first time the Evil Eye chose to use a skill, it uses the first entry in that list (a damaging Gaze). The Evil Eye's location in the spell list has no bearing on where it is in its skills list and vice-versa. Should it cast the last spell in its spell cycle, it will begin selecting from the start of the list once more. In our example, that would mean to cast Thundara and move to Hold the next turn that it picks to cast. Skills work identically to spells for their respective cycle.
Note that for the Anniversary Edition and onward, Chronodia breaks this convention of AI. While she works the same as every other enemy in terms of selecting spells, skills or attacks, Chronodia is scripted to always cast Seal every five turns.
Enemies appear through random battle. They are referred to as Fiends who are the spirits of the dead turned into monsters from negative emotions.