Eternal Legend - Final Fantasy IX
Final Fantasy IX Mechanics

Experience and Levels

For it is written that you will go out into the world and slay of the beasts therein, and in doing so become stronger and more shiny.

The cycle of combat and reward is a staple of gaming in general, and nowhere is it more apparent than among the workings of an RPG. Fighting monsters reaps tasty experience points, which in turn strengthen the party in order to face tougher foes. By analysing the steps of this numerical dance, it's possible to discover precisely how it works.

Note: This is an in-depth look into the mechanics behind the Final Fantasy IX experience system, with suitable mathematical content. It almost certainly won't help Zidane and company to know this, but is provided for the completists out there.

Summary
Spoils

The first logical part of the cycle lies in gaining experience points (XP). Every creature is worth a certain amount of XP, though bosses are typically worth none. After a battle, the total XP for all slain creatures is added and divided equally among the fighters. Characters KOed, or suffering under Petrification, Virus, or Zombie, are not welcome to receive spoils. Thus, each of a party of four will gain much less experience than a lone fighter. AP, used to learn abilities, is not divided up, and all appropriate party members receive the full amount.

Levels

When a character earns so many XP, he will gain a level and become stronger. Extra points will count towards his next level, so none is wasted and it is possible to jump up two or three levels at once. The XP thresholds are given by the following formula:

XP required to reach level x: (x4 + 10x3 + 37x2 + 56x - 96) / 16

XP is cumulative, so reaching level 10 (1510XP) requires only 432XP after reaching level 9 (1078XP). A whopping table of experience points is available for those unable to evaluate quartics in their heads.

Attributes

Of course, levels are of little worth alone. More interesting is their effect on attributes, boosting vital statistics for combat. The formulae involved are quite simple, but contain an interestingly deceptive element which will be revealed later.

Every character has an immutable set of base attributes. These are their stats at level 1, and cannot change.

CharacterSpeedStrengthMagicSpiritStones
Zidane2321182318

From there, attributes are determined by adding on a multiple of the character's current level as given below:

AttributeFormula (round down)
Speed0.1 * Level
Strength0.3 * Level
Magic0.3 * Level
Spirit0.15 * Level
Stones0.4 * Level

Thus, a level 17 Zidane will have (18 + 0.3 * 17) = 23 Magic, for example.

The catch

However, it's not quite as simple as that. Each attribute has an additional booster which grows over time based on current equipment. This bonus is applied on leveling up.

AttributeAdditional points per level
Speed0
Strength3/32
Magic3/32
Spirit1/32
Stones5/32

If the character is wearing any attribute-boosting equipment when they level up, however, then its boosters are also added at a rate of 1/32 per point per level. As an example, consider the Glass Buckle, which temporarily adds 1 to Strength and Magic, and 2 to Spirit. If a character gains a level while wearing it, these boosters will "bleed" into their natural attributes.

AttributeAdditional points per level while wearing Glass Buckle
Speed0
Strength3/32 + 1/32
Magic3/32 + 1/32
Spirit1/32 + 2/32
Stones5/32

Note that this only applies to the base attributes. Defence et al will not increase with levels.

An example

Perhaps the best way to see what's going on is to watch it in action. Consider Zidane, freshly landed in Evil Forest at level 1.

Level 1

AttributeBaseLevel multiplierAdditionalTotal
Speed230.1 * 1 => 0023
Strength210.3 * 1 => 0021
Magic180.3 * 1 => 0018
Spirit230.15 * 1 => 0023
Stones180.4 * 1 => 0018

He ventures into the swamp, fights a few goblins, and levels up.

Level 2

AttributeBaseLevel multiplierAdditionalTotal
Speed230.1 * 2 => 0023
Strength210.3 * 2 => 03/32 => 021
Magic180.3 * 2 => 03/32 => 018
Spirit230.15 * 2 => 01/32 => 023
Stones180.4 * 2 => 05/32 => 018

By the time he reaches Dali, he has fought his way to level 5 and is beginning to show signs of improvement.

Level 5

AttributeBaseLevel multiplierAdditionalTotal
Speed230.1 * 5 => 0023
Strength210.3 * 5 => 115/32 => 022
Magic180.3 * 5 => 115/32 => 019
Spirit230.15 * 5 => 05/32 => 023
Stones180.4 * 5 => 225/32 => 020

Much later, he reaches level 10, still without using any special equipment.

Level 10

AttributeBaseLevel multiplierAdditionalTotal
Speed230.1 * 10 => 1024
Strength210.3 * 10 => 327/32 => 024
Magic180.3 * 10 => 327/32 => 021
Spirit230.15 * 10 => 19/32 => 024
Stones180.4 * 10 => 445/32 => 123

Here he acquires a Glass Buckle. The future path now depends on whether he equips it as he levels up:

Level 20

AttributeBaseLevel multiplierAdditional (Standard)
Gained 19 levels
TotalAdditional (With Glass Buckle)
Gained 19 levels, 10 with Glass Buckle
Total
Speed230.1 * 20 => 2025025
Strength210.3 * 20 => 657/32 => 12857/32+10/32 => 229
Magic180.3 * 20 => 657/32 => 12557/32+10/32 => 226
Spirit230.15 * 20 => 319/32 => 02619/32+20/32 => 127
Stones180.4 * 20 => 895/32 => 22895/32 => 228

By wearing the Buckle for a few hours, Zidane has "absorbed" some of its power and permanently boosted his natural attributes. Of course, wearing the Buckle also adds a temporary attribute boost which isn't included in the above table.

Yes, yes, but what about the important things? You haven't mentioned HP or MP yet

Busted. HP and MP don't follow this formula, nor do they have a easy calculation. Instead, HP and MP are a function of Level and Strength or Magic. After all level multipliers and additionals are added, as in the tables above, HP is worked out by multiplying Strength by a special number which changes for each level. MP is similarly linked to Magic.

The level 20 HP multiplier is around 34.67, so in the above example "standard" Zidane would have (34.67 * 28) = 971HP, while the Buckled Zidane would enjoy (34.67 * 29) = 1005HP.

Multipliers increase almost linearly with level, up to approximately level 40. There they begin to level out, becoming almost constant by the time they reach level 50.