The Making & Usage of Magical Runes
A magical rune is an engraving made upon any surface that has had a spell cast into it, filling it will magic of whatever type intended by the caster. Runes are a common way of making magical effects last longer, or only occur when a certain trigger phrase or action is said or done. To actually make a rune, not much is needed. First, you must know the symbol that represents the type of magic you wish to have the rune cast. If you notice, every spell page has an emoji. Those emojis are the symbols required to make a rune of a specific magic type! Second, you must have some sort of etching tool strong enough to etch your chosen symbol into your chosen surface; whether it be rock, metal, or flesh. In terms of how big the rune must be, there's no limit, but if the rune isn't big enough to hold the mana you pour into it, it will result in deadly side effects. Increasing the size of the rune serves to disperse the mana held within it and decrease volatility. Third, once you have created your rune and the chosen symbol is correct, cast the spell you wish for the rune to emit into the rune itself and pick a trigger action or phrase. When the trigger action or phrase is performed or said, the rune will cast the chosen spell from it, up to the same amount of times the spell can normally be cast. If not triggered, the rune can hold this spell indefinitely until it runs out of the mana used to cast it (the spell runs out of casts, which is dependent on tier), the structure the rune was etched on breaks, or the mana is absorbed out of the rune If there's enough space, you can etch multiple runes onto the same thing.
Enchantments
If the object you choose to engrave a rune on is an item, a piece of armor, or a weapon, the rune has a different name: an enchantment. These behave similar to how normal runes work, but still are unique and different. Enchantments follow the same rules as runes; pick a spell you want on an object, etch the symbol of the type of magic you want on an object, and then cast the spell into the rune. However, at least with armor and shields, enchantments are capable of taking in raw mana from a specific element, for example, fire mana, and giving the wearer of said armor a resistance to that mana, such as fire resistance from fire mana. Unlike runes, though, the stronger the enchantment means the stronger the item being enchanted must be. This means low-level gear can't have high-level enchantments on it. For example, if you attempted to enchant a low-quality chestplate with tier 7 fire resistance, it'd start to melt.
A picture of a blacksmith well-known to the people of Galron, Minos, enchanting a sword with Flame Blade.