Taol

A taol or toal (either name was correct ) was a Waterdhavian coin worth two gold pieces in the city, but outside Waterdeep these coins were practically worthless.

Description
The toal was a square brass coin with a hole in the center to allow it to be strung on a string. The coin was a square about 2 in (5.1 cm) on a side and the central hole was large enough to fit a nib inside.

History
In the late 15 century DR, taols could be exchanged for other currency in the Palace of Waterdeep with no exchange fee, but the line was so long that appointments frequently needed to be made a day in advance. The Guild of Trusted Pewterers and Casters and the Jewelers' Guild were also capable of quickly and reliably performing the exchange.