From Final Fantasy Wiki

Final Fantasy Final Boss
Chaos
#128
Japanese	カオス
Romaji	Kaosu
NES Name	Chaos
PS Name	Chaos
GBA Name	Chaos
PSP Name	Chaos
NES Stats Statistics HP Attack 2,000 N/A Defense Magic Defense N/A N/A Agility Accuracy N/A N/A EXP Gil 0 0 Elemental Affinities Fire Bolt Ice Dia {{{NES Fire}}} {{{NES Bolt}}} {{{NES Ice}}} {{{NES Dia}}} Location Temple of Fiends (Past) Abilities INFERNO, SWIRL, CRACK, TORNADO, SLO2, ICE2, ICE3, LIT3, FIR3, CUR4, FAST, NUKE Resistant to N/A PS Stats Statistics HP Attack 4,000 100 Defense Magic Defense 100 200 EXP Gil 0 0 Elemental Affinities Fire Bolt Ice Dia {{{PS Fire}}} {{{PS Bolt}}} {{{PS Ice}}} {{{PS Dia}}} Location Temple of Chaos (Past) Abilities Blaze, Tsunami, Earthquake, Tornado, Slow2, Fire3, Bolt3, Ice3, Cure4, Haste, Flare Resistant to All GBA Stats Statistics HP Attack Intelligence 20,000 170 40 Defense Magic Defense 100 200 Agility Accuracy Evasion 50 200 100 EXP Gil 0 0 Elemental Affinities Fire Lightning Ice Dia Resist Resist Resist Misses Location Chaos Shrine (Past) Item Dropped Nothing Abilities Blaze, Tsunami, Earthquake, Tornado, Slowra, Firaga, Thundaga, Blizzaga, Curaja, Haste, Flare Resistant to Earth, Time, Paralysis, Darkness, Silence, Mind, Stone, Poison, Sleep, Confusion, Death PSP Stats Statistics HP Attack Intelligence 20,000 170 40 Defense Magic Defense 100 200 Agility Accuracy Evasion 50 200 100 EXP Gil 0 0 Elemental Affinities Fire Lightning Ice Dia Resist Resist Resist Misses Location Chaos Shrine (Past) Item Dropped Nothing Abilities Blaze, Tsunami, Earthquake, Tornado, Slowra, Firaga, Thundaga, Blizzaga, Curaja, Haste, Flare Resistant to Earth, Time, Paralysis, Darkness, Silence, Mind, Stone, Poison, Sleep, Confusion, Death

Chaos is the final boss of the original Final Fantasy.

Strategy

Chaos is the toughest enemy in the game in the Nintendo Entertainment System/PlayStation versions, and one of the toughest enemies in the Game Boy Advance/PlayStation Portable versions. He has a plethora of powerful and debilitating spells at his disposal. The most commonly used spells are Firaga, Thundaga, and Blizzaga, however, these are his weakest spells. Chaos' stronger spells are Blaze, a strong Fire-elemental attack, Tornado, a strong Wind-elemental attack, Tsunami, a strong Water-elemental attack, and the Instant Kill, Quake, all of which are attacks used by the Four Fiends. Rarely, Chaos will conjure Flare, his strongest spell. In terms of status effects, Chaos has Slowra, which can decrease the Hit rate of one character, Haste, which increases his Hit rate, and Curaja, which heals him fully.

It is wise to give three of your characters a Ribbon. In the Nintendo Entertainment System/PlayStation versions, there are only three Ribbons, so one of your characters will have to make do without a Ribbon. It is recommended that you give the Ribbons to your mages. In the Game Boy Advance and PlayStation Portable ports, you can get a fourth Ribbon, so you can give Ribbons to all of your characters. The ribbons will decrease the power of all of Chaos' spells, except for Flare. Protect Rings are also recommended, as they will protect your characters from Earthquake. Slowra can be countered with Haste.

Cast Haste on all your physical attackers. Temper does not work in the Nintendo Entertainment System version, but if you are playing any other version, cast it. Chaos is highly resistant against magical attacks, so opt for weapon strikes. Have your physical attackers use the Giant's Glove, then attack. Have your White Wizard or Red Wizard heal every turn, and have your Black Wizard cast Temper on everyone. If you are playing the Nintendo Entertainment System version, then have your Black Wizard aid in the healing with a Heal Staff or a Heal Helm.