Hi guys, was just wondering if rune slots on crafted armor or weapons use a luck factor, smith level, player level or maybe something else?

Crafting Rune Upgrades - have lots of lesser rune in inventory, but when I go to craft rune upgrade, none are shown? If I craft lesser runes, these are shown. Any trick to getting all inventory runes shown in crafting rune upgrade?

The number of slots is a predetermined number for each item, no luck is involved (except in what armor/weapon) you might find. Player level factors in somewhat. The higher your level the more likely you are to find higher level armors which have better stats. If you are doing one of the witcher sets (cat, gryphon, bear) as you upgrade the armor and weapons more slots will be crafted. (number of slots stays the same going from superior to master crafted).