I was too lazy to work out how to use Weapon/Armour/Item script and to lazy to look for another makin tut, se heres a event thingy to advance equipment with certain items.
1. First, make a few new items. Name them what your materials are. Also find some icons for them as well. Steel Booster and Metallic Connector in my case:
2. Make a new event and make a conditinal branch. Make it say you need a material, my 'Steel Booster for example. Then make another branch under the first line saying you need the other piece (My Metallic Connector). Also, put in a Text Entry at the else for the first material to say you need it:
3. After that, in the new 'Else' line for the second material put in saying u need this material. Then under the conditinal branch last made add in another branch saying you need the item/armour/weapon you are upgrading is in your inventory:
4. Lastly to finish up, in the new else spot put in you need the weapon/item/armour in your inventory to upgrade it. Then in the conditinal branch left over add in decrease item/armour/weapon to the two items to mix and the weapon/armour/item you are upgrading in decrease to. And finally add in, increase for the item you result with and then put in a text entry saying you obtained the item. Also, if you want add in other things.
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If I missed anything tell me