Shield

There are several types of shield in Runescape, including other items that can be worn in the shield position, but the most common are the metal square and kite.

Square shield
Actually rectangular in shape, and may be smithed in all metals and also found in black. It is weaker in all areas than the kite shield, but has lower magic penalties. The smithing level required is 8 above the base level for any metal, and the highest shield available in free-to-play region stores is the Mithril square.

The anti-dragonfire shield also has the same shape as a "square".

Kite shield
Better in all areas than the square shield, other than the magic penalty. Getting hold of a good kite shield in free-to-play requires a high smithing level, or trading with other players who are either members or accomplished smiths of high level. The smithing level required is 12 above the base level for any metal, and at 62 for a Mithril kite, the gap between levels is already becoming large.