Duplicating an item
This simple quick tutorial will show you how to duplicate an item, keeping the same statistics and mesh and icon paths, but allowing you to edit it without affecting the original item in game. This is very simple, and works for just about everything. (Don't try this method for scripting)
First off, open the construction set and go to *Weapons *Silver
Here is the silver longsword and its ID: WeapSilverLongsword
Double click on it. It should look like this with WeapSilverLongsword in the ID area.
Change it to whatever you want, but make it unique. It's best to have order to the ID rather than a big jumbled mess of letters and numbers. Try to keep the first 3 letters actual letters instead of numbers. I forget if this is relevant outside of scripting, but to be safe let's say it is.
It asks if you want to create a new form using the unique ID. CLICK YES! OMG CLICK YES EVERY TIME. Never change the ID of an existing item. EVER. There is not only no need for it, but it can potentially screw up the entire game with one tiny mistake. If you want to EDIT or CHANGE values of that particular item, leave the ID alone and just click Okay. It will save all the changes globally to every Silver Longsword in the entire game but not screw the game up.
Now you can see alphabetically that RSilverLongsword exists. It has all those saved variables.
The reason this is best is because it duplicates all the information for that item, INCLUDING the linked path to the mesh which is packed in the .BSA file, which you can not get into without a BSA unpacker, and it is highly recommended you not even mess with that unless you know exactly what you are doing.
You can not go and search through the .BSA file to find silverlongsword ever and link it to the path in the mod. You actually have to extract it. This is why we duplicate existing items if we want the vanilla 3d model. It will look, act, sound, interact, and be used the exact same way as a Silver Longsword is, but the variables can changed. I made it stronger, cost more, more durable, reach further, and weigh less. So far this weapon doesn't officially exist because I haven't put it in game. It will not replace WeapSilverLongsword because it has a new ID and I chose to make it a NEW ID rather than a replacement. I would have to go to the Interiors section (or exterior) find a place to drop this item and drag and drop the ID of my weapon somewhere in game. Press F to make it fall to the ground, or you have the chance to make it float leagues above the treetops, and, unless you know console commands, forever unreachable.
This works the same for things like NPCs, Doors, Activators, ETC. This method is not only the most widely used in modding, it's the most useful.
A neat trick to do is to drag the vanilla object in the render window, double click it, then go to the properties that you see in the second image, and change it there. This will mean that not only will there be a new ID and duplicated item safely keeping the vanilla object unedited, but that object I just duplicated is already in the render window ready for use and I can simply Ctrl C (Copy) and Ctrl V (Paste) the item over and over should I need it. This saves me time and frustration from finding the new ID in the large list, especially if I begin my ID with a letter in which there are either a lot of or none of and it can be difficult to locate that ID among the jumbled plethora of other IDs.
Be well, sleep well, fight well, live long.
Kudos if this helps!