Tags

Tags are really simple, when you think about it. A tag is a simple true-false conditional. It can be used to determine whether it is true or false that:

-you have an item

-you are talking to a specific NPC

-you have accomplished a certain task

-you are riding a specific vehicle

I guess that means an example is in order... Okay, assuming you are new, go build a map. I can wait. Anyway, now create/draw some NPCs and your hero. You only need two NPCs, and they don't have to be good, just visible. Now create an item. Create two text boxes that roughly convey the following messages:

-here's an item!

-you have the item!

Place the two NPCs. Set one to give you the item(by telling the text box to give you the item when you trigger it) and the other to appear only if tag 2 is set, and say you have the item.Now, set the item to set tag 2 when it's in your inventory. Save, and start the game. Talk to the person there, and they will give you the item. The other person will appear. If you talk to them, they will congratulate you for obtaining the item!

Now go read the several tutorials required to understand that.