Pirates use ships that are similar to the player's ships, but have lower health, fewer cannons, and feature black sails and a darker color scheme.
Carrying valuable items and cargo increases the chance of encountering pirates, as does undertaking certain tasks. In Tradewinds 2 and Tradewinds Legends, possessing certain items can increase or decrease the odds of encountering Pirates.
The strength of the pirate fleet is directly related to your own fleet strength: The stronger your fleet is, the stronger the pirates will be. Pirate fleets will also gradually get larger and tougher as time goes by, making investments in combat capabilities necessary in the long run.
Apart from appearing out in the open sea, pirates are also capable of garrisoning ports during certain quests. Such a port will be marked with a large warning marker on the world map to warn the player. Apart from ships, pirates will also use land-based fortifications such as forts, bunkers and towers to attack the player (also via cannonballs). Sailing to a hostile port does not prevent more pirates from appearing en route, so the player may potentially have to fight two consecutive battles before being able to dock.