Before people discovered the atomic elements, they hypothesized the existence of other elements that, as they thought, comprised the world around them. There were the classical elements:
Earth,
Fire,
Water,
Wind, and often
a fifth element (not
Heart). Sometimes it was
Ice, sometimes it was
Lightning, sometimes
Metal, sometimes nothingness (
Void), sometimes
Darkness, or even
Light, and all will be counted here.
So these are tropes dealing with these old world elements.
Try not to get caught up in them, unless you have a counter element ready.
Tropes: