Yankee Trader takes place in a future where trade barons and mercenaries rule. The player begins with a small space ship, and can advance in power in wealth by trading.
The game's universe is divided into sectors linked more or less randomly, with a combination of two-way links and one-way links. Players traverse these sectors looking for ports, planets, and enemies.
Players can buy commodities, transport them to other ports and sell them, hopefully for a profit. Prices vary by port, and prices change as a port's balance of commodites changes.  As in TradeWars, the process of trading can be tedious. Yankee Trader addresses this problem by allowing players to program macros within the game itself.
The default size of the galaxy is 3,000 sectors, but this can be changed by the sysop. A larger galaxy allowed more players to effectively hide.
Like the majority of BBS door games, gameplay in Yankee Trader is asynchronous: only one player can play at a time. Each player, therefore, is limited to a certain number of moves per day. This number is also configurable by the sysop. When a player exhausts his moves for the day, his ship will remain whereever it was. Various defenses can be set up in case the player's ship is encountered by another player.
Colonizing planets, protecting them by building massive fleets, battling other users' planets and trade routes were also a major part of the game.
Two types of computer controlled characters, the Xannor and mercenaries, also made moves during a nightly maintenance event. In various ways these computer controlled characters add additional threats to stationary defenses and planets (stealing resources from or directly attacking them), and benefits to active players. Players who locate mercenaries can bribe them to join and players who kill Xannor receive additional charge per day and also generate sales at Earth.
Davenport has said that he no longer has the source code for Yankee Trader.
One unresolved exploit exists in the gameplay. Ownership of "Earth" allows a player to recover all money spent at Earth. This effectively allows multiple players or a single player with multiple accounts to purchase an unlimited number of fighters, ground forces, and shield batteries because the money is never used up, only transferred back and forth between two accounts without loss. A patched version of the game exists that prevents this exploit.
- Baker, Derek; Wice, Nathaniel, eds. (1994). netgames. Michael Wolff & Company. p. 146. ISBN 0-679-75592-6.
Trade barons and mercenaries rule the day, and you, with only a small space vessel but great ambitions, are prepared to set out and become one of them.
-  Yankee Trader Instruction Manual
-  History of Trade Wars Variations - John Pritchett
-  Wikia - Trade Wars
-  BBSFiles.com forum
-  Yankee Trader v3.6 Strategy Guide