A copper coin (cp) is a lesser denomination of the silver coin (10:1).
Since one Silver Coin is typically day's wage for a unskilled laborer, day-to-day living expenses are usually priced in copper coins.
A mug of ale: 4 cp.
A loaf of bread: 2 cp.
A commoner's daily meal: 6cp
A tax for a commoner to enter the gates could be 1 cp;
for a noble it could be 1 sp to 1 gp.
Each coin weights about 1/3 of an ounce. Fifty coins always weigh a pound, no matter the type of coin.
Lore: this was set to standardize trade by merchants and guilds.
A tarnished copper coin glints faintly, its edges worn smooth. Intricate runes etched deep catch the light, while a faint metallic tang lingers. It hums softly, pulsing with faint warmth against the skin.