Is a boost to AC is more powerful than a ring that gives 3 Wish Spells, for free, to anyone? Maybe, but I think that a Ring of Invisibility for a Rogue is even better.
Yes, more AC is nice and it can defend against a lot of different things. However, remember that their are ways to get around AC. Fall Damage is the most deadly, and often the most prevalent force in the game. Lots of Spells, Features, and Items go against Saves. Then there is Power Word: Kill: "Are you at 100HP?" "Well yes, but all my defenses are fantastic." "Don't care, your dead, no Save, no prevention."
When creating a Magic Item, those that are presented in the Dungeon Master's Guide are a good way to measure its quality and what is acceptable, but it isn't a pure calculation. A +3 Armor is indeed Legendary, but Efreeti Chain is plain a just better version of +3 Chainmail while both are still Legendary. What's the difference? Attunement. When making Magic Items it is important to know what should require attunement and what should not. Generic +3 Armor is an eventual upgrade to a character, Efreeti Chain is an important decision to be made. A Character can only Attune to three items. Not having an Attunement requirement can make a Magic Item more valuable. Cape of the Mountebank is a great item to have because it allows you to cast a Spell without resources, it does not require Attunement, and you can still wear Armor with it.
While making Magic Items remember that in addition to the Rarities, there are two other ideas you could experiment with: Intelligent Items and Legacy Items.
Intelligent Items are usually more powerful than average, but the Item almost always requires Attunement and it will not Attune with a character that it hates or considers an enemy. They make great Artifact Weapons and Roleplay opportunities.
Legacy Items don't have official rules in 5th Edition, but the basic idea is that they are Magic Items that you "level up" by completing certain objectives. You can have a Legacy Item attached to a specific character's family, and have it have a legend that the character recreates as the campaign progresses. It may start out as a mere Trinket, but eventually become an Artifact of great power, perhaps something necessary to the overarching plot of the campaign.
If a legendary item doesn't have a boost to AC is it really legendary?
Also, send help. I've become addicted to homebrewing items for my players.
My Homebrew Backgrounds | Feats | Magic Items | Monsters | Races | Subclasses
Is a boost to AC is more powerful than a ring that gives 3 Wish Spells, for free, to anyone? Maybe, but I think that a Ring of Invisibility for a Rogue is even better.
Yes, more AC is nice and it can defend against a lot of different things. However, remember that their are ways to get around AC. Fall Damage is the most deadly, and often the most prevalent force in the game. Lots of Spells, Features, and Items go against Saves. Then there is Power Word: Kill: "Are you at 100HP?" "Well yes, but all my defenses are fantastic." "Don't care, your dead, no Save, no prevention."
When creating a Magic Item, those that are presented in the Dungeon Master's Guide are a good way to measure its quality and what is acceptable, but it isn't a pure calculation. A +3 Armor is indeed Legendary, but Efreeti Chain is plain a just better version of +3 Chainmail while both are still Legendary. What's the difference? Attunement. When making Magic Items it is important to know what should require attunement and what should not. Generic +3 Armor is an eventual upgrade to a character, Efreeti Chain is an important decision to be made. A Character can only Attune to three items. Not having an Attunement requirement can make a Magic Item more valuable. Cape of the Mountebank is a great item to have because it allows you to cast a Spell without resources, it does not require Attunement, and you can still wear Armor with it.
While making Magic Items remember that in addition to the Rarities, there are two other ideas you could experiment with: Intelligent Items and Legacy Items.
Intelligent Items are usually more powerful than average, but the Item almost always requires Attunement and it will not Attune with a character that it hates or considers an enemy. They make great Artifact Weapons and Roleplay opportunities.
Legacy Items don't have official rules in 5th Edition, but the basic idea is that they are Magic Items that you "level up" by completing certain objectives. You can have a Legacy Item attached to a specific character's family, and have it have a legend that the character recreates as the campaign progresses. It may start out as a mere Trinket, but eventually become an Artifact of great power, perhaps something necessary to the overarching plot of the campaign.
Excellent food for thought. TYVM.
My Homebrew Backgrounds | Feats | Magic Items | Monsters | Races | Subclasses