One major variety of the 1803 Draped Bust Half Dollar features a small "3" in the 1803 date. The "3" is noticeably smaller/thinner than the large "3" variety and is also missing a serif at the very top-left end of the "3".
One major variety of the 1803 Draped Bust Half Dollar features a large "3" in the 1803 date. The "3" is noticeably larger and wider than the small "3" variety and also includes an additional serif on the top-left tip of the "3".