Flanking: Positioning two hostile creatures on squares that are adjacent to opposite corners of the target creature will result in a temporary +2 modifier to melee attack rolls on the target creature as long as the two hostile creatures are positioned as such. This is treated the same as advantage on the attack roll for all purposes except the additional die rolled on the melee attacks due to advantage (I.E. for a rogue's sneak attack).
Stacking advantage/disadvantage: If a creature has multiple conditions that would cause the creature to have advantage or disadvantage on a d20 roll, for each additional die of advantage/disadvantage, one more unique condition is required than the previous number of condition(s) that caused the previous instance of advantage (E.G. 1 condition = 1 die of advantage/disadvantage, 3 conditions = 2 die of advantage/disadvantage, 6 conditions = 3 die of advantage/disadvantage, etc.).
(Test house rule from Boris)
Enchantments on weapons/armor/shields will be in the form of sockets.
For example, a +1 weapon, will have a gem of +1 socketed into it, to give it magical powers of the gem.
A weapon/armor/shield can have ONE socket added to it if it doesn't already have one for a price. You may come across items that have more than one socket available to them. You cannot stack the same enchantment into said items. Meaning no (2) +1 gems in the same sword/shield/armor. But you can for example, have a +1 gem, and a Frostbrand Gem and or any other enchantment.
Not just anyone can correctly place gems into weapons and armor. A smith who is proficient with smith tools is required.
This is a test and I will refine it in game as needed. We will be implementing this in our next session. I want to try this out so I don't have to "roll" exact items for the party, and keep flexible with items.