List of unacquirable items

In the Golden Sun series, there are some items that cannot be obtained through normal gameplay. Many of these were originally going to be in the game, but were removed from the final version for reasons unknown. Such content in video games in general is referred to as "dummied content". Despite this, the items themselves remain coded into the game cartridge and can be acquired with a hacking device. There are also some items that, while not available to players, are used by enemies.

And then there's the Wheat Sword, a fan-made rumor that just plain doesn't exist.

Items used exclusively by enemies
Signal Whistle: A consumable item used by Briggs in Golden Sun: The Lost Age to summon additional Sea Fighters. Briggs possesses three of these, and the summoned Sea Fighters do not begin fighting until the following turn. If hacked into the party's inventory, its icon is that of a coin. It disappears after use, much like consumable items, but differs from most consumable items in that it cannot be stacked. Coincidentally, it also cannot be sold. If used by a party member during battle, it summons a Sea Fighter to the enemy's team. Fireworks: A consumable item used by Ku-Embra in Golden Sun: Dark Dawn. It targets a single member of the player's party and places one of that character's Djinn in Standby mode. It has a purchase value of 30 coins. If hacked into the party inventory and used against an opponent, the command and visual will carry out, but the game will then report "But it had no effect!" because opponents do not have Djinn available. Firecracker: A consumable item used by Blados during his first battle in Dark Dawn, as well as by the final boss of the same game. It deals a Mars-based attack with a power rating of 140 and a range of five targets. It has a purchase value of 400 coins.

Dummied items
Kusanagi: A Light Blade in the original Golden Sun. It lacks an Unleash, but is otherwise the most powerful Light Blade in the game. Its graphic would be recycled for the Masamune in Golden Sun: The Lost Age. In fact, hacking a Kusanagi into a Golden Sun party's inventory and transferring it to The Lost Age results in the Kusanagi being replaced with a Masamune. Casual Shirt: A Shirt in Golden Sun: The Lost Age. Can only be equipped by male characters and provides small boosts to HP and Defense. Likely intended to be a new Lucky Wheels prize. Herbed Shirt: A Shirt in Golden Sun: The Lost Age. Provides small boosts to Defense when worn and can be used to restore some HP, equivalent to an Herb. Likely intended to be a new Lucky Wheels prize. Divine Camisole: A Shirt in Golden Sun: The Lost Age. Can only be equipped by female characters and provides small boosts to Defense and Luck. Likely intended to be a new Lucky Wheels prize. Rainbow Ring: A Ring in Golden Sun: The Lost Age. Can be used to attempt to inflict up to three enemies with Delusion. Likely intended to be a new Lucky Wheels prize. Soul Ring: A Ring in Golden Sun: The Lost Age. Can be used to revive a fallen ally to full health. Likely intended to be a new Lucky Wheels prize. Aroma Ring: A Ring in Golden Sun: The Lost Age. Can be used to restore some HP to all active party members. Likely intended to be a new Lucky Wheels prize.

Formerly-unacquirable items
The following items were unacquirable in previous games, but later became acquirable:

Sol Blade: A Long Sword coded into the original Golden Sun, but would not become available until Golden Sun: The Lost Age. It is the strongest weapon in both games, although it lacks its Unleash in Golden Sun. If hacked into a Golden Sun party's inventory and transferred to The Lost Age, it is updated to its TLA form. Masamune: A Long Sword coded into the original Golden Sun, but would not become available until Golden Sun: The Lost Age, at which point it acquires the Kusanagi's appearance. It lacks an Unleash in the first game, but is otherwise a very powerful weapon. Curiously, if hacked into a Golden Sun party's inventory and transferred to The Lost Age, it is replaced by the Fire Brand. The Kusanagi, however, does become a Masamune. Mysterious Robe: A Robe coded into the original Golden Sun, but would not become available until Golden Sun: The Lost Age. In the first game, it does nothing beyond provide an impressive boost to Defense. Ninja Sandals: A pair of Boots coded into Golden Sun: The Lost Age, but would not become available until Golden Sun: Dark Dawn. In The Lost Age, it provides a minor Defense boost and a moderate increase to the Unleash rate. It is likely that this was meant to be a new Lucky Wheels prize. Knight's Greave: A pair of Boots coded into Golden Sun: The Lost Age, but would not become available until Golden Sun: Dark Dawn. In The Lost Age, it provides a minor HP and Defense boost and can be equipped by any party member. It is likely that this was meant to be a new Lucky Wheels prize. Silver Greave: A pair of Boots coded into Golden Sun: The Lost Age, but would not become available until Golden Sun: Dark Dawn. In The Lost Age, it provides a mild Defense and Luck boost and can be equipped by any party member. It is likely that this was meant to be a new Lucky Wheels prize.