The toner rubs off
Toner is being laid down but not melted onto the page. Nine times out of ten it's a paper mismatch: the driver is set to plain paper and you've loaded something heavier, so the printer doesn't run the fuser hot enough. Set the paper type to match what's actually in the tray. Damp paper does the same thing, so try a fresh ream from the middle of the pack. If neither helps, the fuser is worn and that's a service part.