Items and Equipment

Attunement

• Iroa is an "Age of Myth" setting and a relatively wide-magic world. Instead of a flat 3 items, you can attune to a number of items equal to your proficiency bonus. This is actually less to start, becomes equal to the book as published at 5th level, and increases beyond the published limit from 9th level onwards.
• Remember that other than the attunement limit, 5E does not care about item slots, provided that you can logically equip the items together. Want three rings? Sure! Want both a magic cloak and also a magic cape? Sure! Want two separate pairs of magic sandals at the same time? Probably not gonna fly!

Bronze Age

• Any metal gear is generally made of bronze. This functions the same as the items in the PHB. 
  • (The iron age didn't start because iron and early steel were better than bronze - they're actually worse - but because iron was much easier to get your hands on after trade networks disintegrated in the Bronze Age Collapse. But tin and copper are relatively abundant in Iroa, and iron is scarcer.) 

Free Interactions

• Instead of only one free object or environment interaction per turn, you can take one as part of, before, or after your movement, your bonus action and your action, for a total of three free interactions per turn. 
• You can use both hands to do two item interactions simultaneously for the price of one, if it makes sense and would not require overt focus or cause overt distraction.
• For example, unlike in core where dual wielders are screwed, you actually can draw both of your weapons at once, instead of only being able to draw one and then have to use an action for the other. Likewise, if you have two attacks, you could attack in melee, stow your weapon as your free action that is part of the attack, take your move, draw your bow as your free interaction while moving, then take your second attack with the bow.
• Free interactions are for items that are readily accessible, such on a table, on your belt, slung to your back on a bandolier, etc; and for interactions that are basically a single simple motion, like drawing or stowing a weapon, opening or closing a door, etc. Pulling an item out of a backpack, working a lock, and so forth are not free.

Holdout

• Sometimes, you realize too late that you should have bought or prepared something the last time you were in town. But just because you the player forgot, does not necessarily mean that your character would have forgotten!
• As a bonus action, you can declare a holdout item up to once per point of Wisdom bonus. You retroactively spend money equal to the cost of an item you had access to the last time you took an extended rest, and you have that item - your character had the insight that it might be useful sometime in the future.
• The maximum cost of the item is your level squared x 25 gp, e.g., 100 gp for a 2nd level character, or 10000 gp for a 20th level character. If you don't have the money, you can't declare the holdout - there is no "credit" for a holdout!
• As something you just had tucked away, the holdout item can't weigh more than 5% (one-twentieth) of your carrying capacity, or your mount's carrying capacity if you find it in your saddlebags.
• Your uses of this ability don't recharge until you take an extended rest in civilization.

Potions and Oils

• Potions and oils can used as a bonus action, after drawing them with your free object interaction. However, applying a potion or oil to someone else is still a standard action.
• If you use a healing potion as a standard action instead of a bonus action, or outside of "encounter time," you are able to apply it carefully to your wounds and drink the rest without losing any, and so heal the maximum amount.
• If you use a non-healing potion as a standard action instead of a bonus action, or outside of "encounter time," the duration of the potion is doubled due to being able to be more careful and make use of every drop without spilling or losing any.
• The Thief Rogue subclass’s Fast Hands ability allows the standard action version of potion use as a bonus action.

Scrolls and Spell Trigger Items

• Items that require you to be able to cast a given spell lose that requirement.
• Anyone can cast a spell from a scroll, wand, staff or the like, regardless of character class. This requires an Arcana check.
• The DC is 10 + the spell’s level. 
  • You get disadvantage on the check if you aren’t trained in Arcana.
  • You get advantage on the check if the spell is on your class's spell list, or if it's not on your list but you can cast spells of that spell level.
• You don’t have to make a check if the spell is on your class’s spell list and you are also high enough level to cast it, or if you are a Thief Rogue with the Use Magic Device ability, or if you are an Artificer of the same level that a native caster would not have to check (eg, Artificer 9 or higher for a 5th level spell).