If an item has sockets, treat the 1 in 6 chance rolls as exploding. So if they have sockets, they have one socket. If you roll another 1 in 6, then they have two sockets. If you roll a third 1 in 6 in a row; then they have three sockets. At this point, stop rolling, as only legendary or special items have more then three sockets. Items also have a maximum number of sockets based on their size. For weapons, it's the damage die; 1d4 = 1 max socket like a dagger with a jeweled hilt. For 1d6 weapons like swords and axes its 2 sockets, and finally greatswords and polearms can have up to 3 sockets; embedded along the hilt, or inside the meaty head of the great war mallet.
Finally, sockets are always found empty unless the item was already owned; most socketed weapons found in ancient tombs had their gems pulled out and the item left to collect dust.. You can insert a socket with a gem whenever you wish as long as you're in town. Dwarves in the party have the innate crafting skill so they can socket a gem with a single turn of downtime and a small repair hammer. You can attempt to remove a gem from a socket, but it will have a 1 in 4 chance to chip the gem and lower its quality by one degree (Dwarves only have a 1 in 6 chance instead). High quality gems become standard, and standard gems become dust and are destroyed. Some gems are inherently more powerful then others; Diamonds, Rubies, Sapphires, Topaz and Emeralds are considered the most valuable and grant the most powerful bonuses.
Every gem has a specific effect based on what it is socketed in and the type of gem. Consult the tables below for each gem type and what they do. Many socketed gems will add a small amount of damage to weapons on a successful hit, or increase resistances when placed in armor, and so on. These gems are elemental in focus, but other types of gemstones may not be; special rune stones, magic crystals, or jewels may have totally unique effects. Regular gems have a basic effect, with high quality gems which are larger or more brilliant have a more powerful, advanced effect.
Weapons- Deals 1 Fire Damage on a hit. Quality Rubies deal 1d4 Fire Damage on a hit.
Armors- Reduce Incoming Fire Damage by -1, Quality Rubies make the user immune to desert heat, and reduce all incoming Fire Damage by -2
Accessories- Wearer gains +1 to their Strength stat. Quality Rubies grant +2 to their Strength stat.
Sapphires have power over cold and are associated with intelligence.
Weapons- Deals 1 Cold Damage on a hit. Quality Gems deal 1d4 Cold Damage on a hit.
Armors- Reduce Incoming Cold Damage by -1, Quality Sapphires make the user immune to tundra cold, and reduce all incoming Cold Damage by -2
Accessories- Wearer gains +1 to their Intelligence stat. Quality Gems grant +2 to their Int stat.
Topaz have power over lightning and are associated with dexterity.
Weapons- Deals 1 Shock Damage on a hit. Quality Gems deal 1d4 Shock Damage on a hit.
Armors- Reduce Incoming Shock Damage by -1, Quality Topazes make the user immune to high altitude sickness, and reduce all incoming Shock Damage by -2
Accessories- Wearer gains +1 to their Dexterity stat. Quality Gems grant +2 to their Dexterity stat.
Emeralds are poisonous and are associated with nature and poison.
Weapons- Save vs poison on hit, take 1d6 damage on a failed save. This save triggers again every turn, with a successful save ending the poison. Quality gems have -2 for enemy saves against this.
Armors- While equipped, you +1 to poison saves. Quality increases this to +2
Accessories- Wearer restores +1 hit points if you sleep or camp in a natural place each night. Quality grants the regular bonus, plus you can go one more day without food or water.
Diamonds are powerful and are associated with purity.
Weapons- Makes the weapon +1. Quality makes it +2. Does not stack with other diamonds.
Armors- Makes the armor +1. Quality makes it +2. Does not stack with other diamonds.
Accessories- Wearer gets +1 to all saves. Quality grants +2 to all saves.
Amethyst are magical and associated with the arcane.
Weapons- Makes the weapon count as a wand or staff for the purposes of needing a spell focus. Quality gems make the weapon's attack ignore magic shields, blocks, or other spells such as Windwall as long as the bow is embedded with an Amethyst.
Armors- Grants +1 to spell saves and grants +1 AC vs summoned creatures. Quality increases the normal bonus to +2 each and makes all defensive spells last a turn longer if they last at least a turn.
Accessories- Grants an additional 1st level spell slot, once per day. Quality increases this to a 2nd OR 1st level spell slot, decided each morning when you prepare spells.
Citrine is associated with wealth and health.
Weapons- Grant nothing.
Armors- While wearing this armor, you gain +2 Maximum Hit-Points. Quality gems increase this to +4 Maximum Hit-Points.
Accessories- Grant protection over enterprises or households. 1 in 6 chance to avoid any disasters or economic failures that would harm your holdings. This only works if you're wearing the accessory for the entire time you are out questing, it's like a homeward charm of protection. Quality gems make this protection grow to 2 in 6, and grain a +5% bonus to income from your holding.
Amber is associated with toughness and rural life.
Weapons- Deals +1 damage to wild animals. Quality deals +1d4 damage to wild animals.
Armors- Grants +1 AC vs wild animals. Quality grants +2 AC vs wild animals.
Accessories- Wearer gains +1 to their Constitution stat. Quality grants +2.
Aquamarine is associated with the scholars and healers.
Weapons- Grant nothing.
Armors- Grant nothing.
Accessories- Wearer gains +1 to their Wisdom stat. Quality grants +2.
Jet is associated with luxury and the old world.
Weapons- Deals +1 damage. Quality deals +2 damage. Attacks with this weapon harmlessly pass through 'pure' beings. Such as virgin maidens, unicorns, monks, all-white lambs, etc.
Armors- Grant nothing.
Accessories- Wearer gains +1 to their Charisma stat. Quality grants +2. This charm works on most lower class people, but nobles see the wearer's charm as superficial.