A relic is any piece of equipment that can't normally be bought in stores. They're weapons and armor with unusual and useful properties, ranging across the scale from an unusual sword nabbed from a treasure chest to the heart of a legendary living weapon, forced into the shape of a blade of burning light.
In game terms, a relic is a piece of equipment with any properties the GM decides. It isn't found on the equipment list, so the players won't be able to buy it from a store unless it's explicitly mentioned by the GM. They might find it in a horde of treasure, be granted it as a gift, steal it from a monster, or create it in a forge.
If a Relic is sold in a store, the GM can probably assign its price as if it were an ordinary piece of equipment of its tier. If it's bought from a store, it might cost as much as a piece of equipment of the tier above, or even more. (These are guidelines, and nothing more - Relics are really a playground for GMs to create whatever toys they wish to grant the players.)
The general process for creating relic equipment works as such:
1. Think of the item, and name it.
2. Determine its type. In the equipment system, it's a certain type of weapon or armor, or a shield. A claw, or a suit of mystic armor, or what-have you.
3. Determine its tier. Probably the tier of the party, or a little above if they're at the top of the bracket.
4. Grant it the base properties of a piece of equipment and that type or tier. The proper delay, special properties, defenses, power, and so on, as suits it. Then change them if you feel like it.
5. Grant it some special properties.
The special properties of a relic might be drawn from the Properties or Equipment-Properties page, but they might be stranger and more powerful - duplicating the effects of a support job ability, boosting a character's power in a certain situation, or applying a special rule. Some considerations for them are listed below.
An Everyday Relic
Equipment with an unusual property that's still on par with the others of a tier can still be compelling, if it comes at a time when it's especially useful. Heroes that find armor warded against fire deep inside a volcano will bless their luck, even though "warded against fire" isn't that exciting of a property on its own.
Tough monsters might drop everyday relics or have them in their Equipment slots. They might be found in ruins or sold at slightly unfair markups by enterprising, mysterious merchants.
Powerful Relics
Relics might also be found that really do have an extra kick to them, compared to other equipment - simply better than anything you would be buying in a store. These might inflict powerful statuses that are difficult to otherwise obtain, such as Curse or Imperil. They might have a pair of handy effects on them, such as MAG +1 and -2D to Spells. Another possibility is a unique effect, such as inflicting +25% damage when an ally is KO'd.
A relic of some power is probably something of some weight within the story. The Atma Weapon, the burning heart of an ancient beast of mass destruction, would probably be a powerful relic. So would the blade Cecil received atop Mt. Ordeals.
They might be found to honor some milestone in the narrative of the game, or some spectacular achievement in play - especially difficult bosses might drop powerful relics, or have them hidden away to be stolen.
Obsolescence
One important consideration for relics is whether or not they will become obsolete - whether, as the heroes ascend in levels and tiers, there's any reason to ever equip anything else. Most relics should probably become obsolete, except near the end of the game. As such, be cautious with powerful effects that greatly outweigh the value of getting higher-tier equipment - Auto-statuses, large boosts to attributes, and so on. Since magic-users don't depend on weapons as much as physical attackers do, be more careful with handing out properties that enhance the use of magic.
Of course, as the heroes near the end of their adventure, feel free to go nuts!
Letting Go
What happens to an obsolete relic? Well, one with no real importance might get sold, or lugged around in case the situation they apply to arises again. However, players might not feel like carrying around a legendary sword around in their packs, forgotten.
As such, depending on the tale of an item, it might be of interest to consider ways heroes can get rid of magical equipment while still respecting their legend - placing them in the care of great blacksmiths until one day the materials can be found to reforge them, embedding them in shrines to seal them with their magic power, gifting them to other respected travellers, giving them to a museum.
Monsters and Relics
Humanoid monsters are capable of equipping weapons and armor. This means that you can easily make a deadly foe by handing an already-skilled enemy warrior a powerful sword or having him don a suit of impregnable armor. If you place the equipment in their drop slot, the players might enjoy picking it up after they've won the fight, and making use of whatever property was giving them trouble a few moments ago.
If you place it in their equipment slot, the heroes will be able to steal it off of them in the middle of the fight. This is hilarious, and I highly recommend it.
Examples of Effects
Here are some examples of unusual, powerful relic properties that have shown up in playtesting. They can probably serve as guidance in creating your own.
"When a weapon ability misses, reroll it at -30 CoS, as per "Zanshin"."
"Critical II, grants Regen (3) and Refresh (3) on a critical hit as opposed to inflicting bonus damage."
"Added Status: Imperil (40)"
Relic Accessories and Relic Items
Making a relic accessory is simple - they simply grant whatever special effect you desire.
Be warned that a relic accessory will never, ever go naturally obsolete, unless it's spectacularly weak.
A relic item is simply an item that, when used, has whatever effect the GM wishes it to. Since they're usually single-use, they're probably not too dangerous.
They'll just do whatever you decide.
Relic Formulae and Relic Loot
In the Remodeling system, you can grant the players special formulae with unique recipes, which allow them to place unique properties on their equipment. Basically, you can grant them the opportunity to build their own relics, using rare loot that's not one of the normal fifteen types.
You could also have them learn of a new formula that does use loot that's of the given 15 types, allowing them to discover a new tool to use in arming themselves throughout the game. This might be an exciting reward for players to hunt for!
Relics in the Bare System
Even in the Bare System, a Gamemaster can still assign relics. It probably isn't done as a matter of course, but if a legendary sword figures in the story, or if one of the players get their hands on a rocket launcher, you might want to add mechanical weight to that. Simply say "Okay, when you're fighting with this, you have these properties," where "these properties" might include changes to Strength, Blocking, Defenses, Style, in addition to any other equipment property. You might also wish to have relics grant additional Sets of special effects, mutually exclusive with the others granted by a Class or Job.
Relics in the Bare System can be proper equipment, but they could also be fearsome kung-fu training, the awakening of a dormant, dangerous bloodline, or something else which can't be "equipped" in a proper sense.
Example Relics
Weapons
Relic weaponry includes everything from legendary weapons to occasional rare finds - anything that can't usually be found in stores. Some Relic weaponry might be purchasable, but it usually isn't, and when you purchase it, it won't be anything near a fair price.
When a game master includes a relic weapon in a game, they choose a tier for it and assign it a power accordingly.
If a Relic weapon is sold, let the game master assign its price as if it was an ordinary weapon of that tier. If it is purchased from a store, it might cost as much as a weapon from the tier above it!
This list is only a suggestion of names and properties, drawing on previous Final Fantasy games. Feel free to invent your own! Each game in the series had characters with their own unique, flashy ultimate weapon - you can always ask the players what they'd like the design of theirs to be, if you're stumped. Each weapon bears some suggested, often unique properties, and a brief description explaining how it might symbolically connect to its incarnations in Final Fantasy games.
Generally, when it comes to designing relics, be more careful with things that benefit actions that aren't weapon attacks than things which merely make attacking stronger. The power of a weapon will become obsolete, but Auto-Faith won't. Feel free to tack extant properties on a weapon that usually doesn't get it, or at a tier that usually doesn't appear, and call that a Relic. The core equipment lists in Seed gloss over many powerful weapons that appeared in Final Fantasy.
The Ultima Weapon
Usually a: Sword, Greatsword
A weapon said to be forged of the breath and strength of the wielder, the Ultima Weapon glows with an unearthly light.
Auto-Bravery, also Auto-Critical Up when HP is full.
Save the Queen
Usually a: Sword, Greatsword, Whip
Emblematic of those bound by their duties.
Resist Confuse and Charm IV, SoS-Protect, damage redirected onto you receives a -50% situational modifier. (Like by Cover or Reflect.)
Dancing Mad
Usually a: Instrument
A weapon that sends battles into chaos.
Added Status: Confuse (20), Auto-Faith, Confused Enemies Have Critical II.
Illumina
Usually a: Sword, Greatsword
A blade shining with light.
Critical II, Spell Critical: Holy, Elemental: Holy, Enhance: Holy.
Ragnarok
Usually a: Sword, Greatsword
A herald spirit of world destruction in guise of a weapon.
Critical II, Enemies Have +20 Drop CoS, +2 Power.
Princess Guard:
Usually a: Staff
Carried by those who wish to protect others.
Inflicts +25% damage per KOed Ally, Enhance Recovery, Resist Death II.
Highwind
Usually a: Spear
A famous weapon carried by great lancers.
Death Penalty
Usually a: Gun
A vicious tool of vengeance.
Critical II. When Bearer KOs an Enemy, they gain their choice of: Bravery (4), Critical Up (4), Tranq (4).
Godhand
Usually a: Claw
Sealed on a distant island, it grants tremendous martial power.
-3 Delay and Floor, Critical II, ATK +2.
Missing Score
Usually a: Gun
A large-caliber weapon designed to settle things once and for all.
+25% Situational Modifier at Full MP, Added Effect: Deprotect (20).
Excalibur
Usually a: Sword, Greatsword
The legendary blade of great cavaliers.
Pain Immune, Power +3, Arcana Killer.
Lion Heart
Usually a: Sword, Greatsword
A marvel of modern engineering, a blazing weapon for those who won't be forgotten.
Critical II, Stop Immune, Slow Immune, Delay -3.
Zodiac Spear
Usually a: Spear
A weapon typically thought to be a myth. It has a way of slipping through your fingers, even once you have it.
Evasion I, Power +8, 20% Chance Of Getting Lost Each Session. (Like Stolen, Or Dropped, Or Destroyed, Or Whatever.)
Brotherhood
Usually a: Sword
A sword with a blade of water, passed down from friend to friend.
Water-Elemental, Power +2, Sensor.
Umbrella:
Usually a: Staff.
A fashionable weapon with some modern charm.
Water Immune.
World Champion
Usually a: Boomerang
A weapon for victorious champions.
Zanmato
Usually a: Sword, Katana, Great Sword.
The blade of a famous bodyguard.
Added Effect: Death (40), Added Effect: Lock (100).
Zantetsuken:
Usually a: Sword, Katana, Great Sword
Odin's famous iron-cutting blade.
Critical I, Added Effect: Death (20). Piercing. (if Already Piercing, Added Effect: Seal Armor (20). )
Valiant
Usually a: Dagger, Gun.
A weapon for those who go on fighting until the end.
Power +2, Gains +50% Situational Modifier in SoS. SoS-Blink.
Venus Gospel
Usually a: Spear
Empowered by years of hard work - for those who won't give up on their dreams.
Auto-Refresh, Critical IV at Full MP
Mythgraven Blade
Usually a: Sword, Greatsword.
The symbolic weapon of a paladin.
Enhance: Holy, Undead Killer, Debravery Immune.
Ame no Murakumo
Usually a: Ninja Blade, Katana.
The true "Heaven's Cloud" of which there are many copies.
+2 SPD, +2 MAG.
Yoshiyuki
Usually a: Sword, Greatsword, Katana
A blade dedicated to final stands.
Inflicts +25% damage per KOed Ally.
Nail Bat
Usually a: Sword, Great Sword, Hammer
Just what it says on the can.
Critical IV, Weapon Accuracy -20
Mythril Weapon
Usually : Anything
Made of a rare, magnificent material, mythril weaponry gleams blue.
Power +2.
Enhancer
Usually: a Sword
A weapon designed to empower the bearer.
Magic Evasion I, +1 MAG.
Rune Weapon
Usually: A Sword
A weapon that draws on magic power, intricately engraved.
Expends 10% MP or (10 x Tier) MP (Whichever is Greater) To Inflict Critical Hits With All Weapon Abilities.
Chainsaw
Usually a: Greatsword, Axe
Occasionally paired with hockey mask.
Added Effect: Death (20).
Drill
Usually a: Spear
Pierces straight through enemy defenses.
Added Effect: Seal Armor (40)
Blood Sabre
Usually a: Sword
A red tinted blade that steals the life energy of those it cuts down
Drains HP
Armor
Rubber Suit
Made from the skin of a Hydra, it is impervious to lightning.
Lightning Immune
Brave Suit
An extremely durable suit for courageous fighters.
Fire Resist, Auto-Regen
Maximillian
Shining armor possessed by righteous knights.
+3 Armor, +3 M.Armor
Genji Armor
The exotic armor of a legendary swordsman.
+10 to Reaction CoS
Robe of Lords
Tailors weep when they look upon its glory.
Auto-Faith
Luminous Robe
Said to be possessed by a spirit of light.
+100 HP, +50 MP, +1 SPR
Mythril Armor
Made of a rare, magnificent material, mythril armor gleams blue.
+1 Armor +1 M.Armor +25 HP