Leather Cap

A Leather Cap is the first Hat-class headwear available throughout the  Golden Sun series.

Basic Description by Game
A Leather Cap increases the wearer's base Defense by 3 points. As a common item, it can be bought repeatedly from Vendors for 30 coins each, and sold for 20 coins each.

In Golden Sun, Leather Caps are sold in Vale and Vault. In Golden Sun: The Lost Age, they are sold in Daila, Madra, and Alhafra. In Golden Sun: Dark Dawn, they are sold in Patcher's Place. Additionally, a Leather Cap is given to Matthew early on as part of a demo showing the player how to equip weapons and armor. In all its appearances, Leather Caps can be equipped by all members of the party.

Analysis
The Leather Cap serves a minor yet helpful role at the start of Golden Sun, when it can be first bought in the starting town of Vale: The three members of your newly formed initial party, Isaac, Garet, and Jenna, do not have any headwear equipped on them whatsoever, so buying multiple Leather Caps with your limited starting money to give to the Adepts is certainly solid. Just be aware that Jenna will only be part of the party until the end of the upcoming Sol Sanctum dungeon, so if you think it's a good plan you can hold off on giving her any defensive equipment, Leather Cap included, and use your funds on bolstering the offenses and defenses of Isaac and Garet, who you will be using for the whole game.

Leather Caps play much the same minor-but-nice role at the start of The Lost Age because two of your Adepts, Felix and Jenna, initially start out without any head protection either. Buying Leather Caps and other defensive equipment for your party with your small amount of starting funds is overall better than buying any offensive equipment because The Lost Age emphasizes rewarding your solving puzzles in the game's dungeons with weapon artifacts far stronger than what you can find in any store.

In Dark Dawn, unlike the previous games, all Adepts will start with headgear of some kind. Karis and Tyrell will both have Leather Caps as soon as they join the party. Matthew will get his as part of a demo showing how weapons and armor are equipped. Thus, buying Leather Caps at Patcher's Place is unnecessary. Later on, Karis will be able to replace her Leather Cap with a Circlet once the party reaches Carver's Camp. However, Matthew and Tyrell will have to wait until they reach Harapa, where Open Helms are found.