Cartography skill is used to make maps and decipher Treasure Maps.

Map Deciphering or Map Decoding works in progress steps. Each time you attempt to decipher a treasure map, a skill check will be made. On a successful check, you will earn a % of progress towards deciphering the map. The amount of progress is determined with a dice roll: (4d6 + toolbonus*0.25)%. When 100% is reached, the map is deciphered.

See: Map Decoding for more information.