There are 8 different professions in Mine Things, each has different bonuses and advantages. Different professions are unlocked as you get more melds.
Miner: Everyone starts as a miner. A miner has no special bonuses. They can send vehicles to explore cities, but they can not use ships.
Unlocked at 10 melds:
Trader: A trader specializes in bringing valuable things across great distances. He can carry anything in his vehicles except for other vehicles or ships. Each of his vehicles gets a +2 inventory bonus. This helps him bring more things including defensive weapons with which to fight off highwaymen.
Highwayman: A highwayman specializes in pillaging. His vehicles can choose which classes of vehicles to pillage and will target those of any profession. Upon success, they fill their cargoholds to the brim with their victim's things. All vehicles receive a 25% attack bonus. Highwayman vehicles can carry weapons to add to their stats but cannot carry anything else. If a Highwayman cannot pay his debts, all his vehicles are grounded until he pays them off.
Guard: A guard restores order to the trade routes by attacking pirates. His vehicles can choose which classes of highwayman to hunt and upon success, they will collect a bounty from the highwayman in gold. If the highwayman has insufficient gold to pay then the guard gets as much gold as the highwayman can pay and a loan which will be paid off as soon as the highwayman gains enough gold. The bounty ranges from 5 to 2500 gold depending on the highwayman's vehicle class. A guard will honor the law and never attack a trader nor another guard. Guard vehicles can carry weapons to add to their stats but cannot carry anything else. Hunting for more information
Unlocked at 20 melds:
Merchant: A merchant can use ships to transport items by sea. They get a +3 inventory bonus, and can transport items from the main land to the island.
Pirate: A pirate is the highwayman of the sea. His vehicles can choose which classes of ships to hunt and will pillage any ships it succesfully beats. A pirate can carry weapons and cannon balls. Pirates also get a 25% chance to score a critical hit when attacking with cannons. If a pirate cannot pay his debts, all his vehicles are grounded until he pays them off.
Bounty Hunter: A bounty hunter earns gold by defeating pirates. If they beat the pirate or sink the pirates ship they will recieve a bounty based on the ship's class. If the pirate has insufficient gold to pay then the bounty hunter gets as much gold as the pirate can pay and a loan which will be paid off as soon as the pirate gains enough gold. A bounty hunter can carry weapons and cannon balls.
Fisherman: A fisherman uses bait and catches fish from the sea. A fisherman can carry weapons, cannon balls and bait. As he travels there is a chance that he catches fish using the bait he has on board. If he catches a fish the bait will be replaced with the fish he caught. If he passes over a shipwreck then he also has a small chance of salvaging any items that may have sunk with the ship.