The Burning of USS Philadelphia (co-op)
The Burning of USS Philadelphia (co-op) is a cooperative Historical Battle in Age of Empires III: Definitive Edition, set in 1803. Two players share control of United States against Barbary Pirates. This mode uses a team-specific objective sequence based on The Burning of USS Philadelphia.
Mission background
The required goals are Capture the corsair ship Mastico by destroying its escort; Seize the outpost at the entrance to the harbour by killing all of its guards; Bring the captured corsair ship to the USS Philadelphia and kill its guards; Defend the corsair ship while the USS Philadelphia is loaded with explosives; The captured corsair ship must reach your frigates at the entrance to the harbor. Optional goals include Rescue the crew of the USS Philadelphia; Capture the fixed gun to open a swifter route to the USS Philadelphia; Destroy the docked Barbary fleet to the east.
Objectives & rules
Secure the named target before committing the whole force elsewhere; keep a mobile reserve near the threatened approach. Scout the named destination and keep the required hero or escort force safe on the route; clear defenders before moving the mission-critical unit into range. Scout the target and its approach, then preserve enough of the starting army to finish the required assault. Scout the route before moving the hero or starting force, and avoid splitting units the mission needs together. Take optional objectives when they add useful allies, routes, resources or reinforcements without putting the primary goal at risk.
Cooperative starting conditions and objectives
This co-op Historical Battle was added to Definitive Edition in update 61213 and is set in 1803. Two United States players start with 250 Wood, a population limit of 60, a Sloop, a Rowboat, and six Marines each. The starting age is Fortress Age in most difficulties and Commerce Age on Hard. The primary objectives are to capture the corsair ship Mastico by defeating its escort, seize the harbor entrance Outpost, bring the captured ship to the USS Philadelphia and clear its guards, defend it while explosives are loaded, then escort the corsair back to the friendly frigates. Optional tasks include rescuing the Philadelphia's crew, capturing a Fixed Gun for a shortcut, and destroying the Barbary fleet at the eastern docks.
Capture the ship and clear the first island
The opening fight is against the Privateers escorting the Corsair. Use hit-and-run ship movement to keep the Sloops from taking unnecessary damage while focusing one target at a time. After the Corsair is captured, use the Rowboats' range to clear guards on the first island. Explosive stores can be detonated to damage groups, reducing Marine losses. The Rowboats are useful here because the players will lose access to them after this section; use their range while it is safe, then land the Marines to finish the guards and seize the Outpost. The objective is to preserve enough force for the infiltration and defense phases, not to defeat every ship in the harbor at once.
Complete optional objectives before the defense timer
Once the players reach the USS Philadelphia area, clearing the guards starts an extended defense against repeated pirate waves. Complete the available secondary objectives before starting that timer whenever possible. Freeing the prisoners at the Stockades adds Marines and, in one location, a Falconet; it can also transfer control of docked Intrepid Privateers. Stephen Decatur can absorb damage while Marines clear the guards, but he has 850 hit points with the listed treasure and regenerates slowly, so heal and reposition carefully. A treasure nearby grants Decatur an additional 30% hit points, while other treasures provide experience. Capturing the Fixed Gun and destroying its bridge can create a faster escape route. These optional gains make the later defense more manageable.
Use the Corsair for stealth and transport
The captured Corsair's flag ability provides a useful movement and stealth tool. Load Marines and support units into it, then sail around patrols rather than trading fire with every ship. Keep the captured Privateers and Rowboat in their original docked positions when the mission route allows it. The Rowboat can clear bridges or approach a dock while avoiding patrols, and additional Rowboats from a shipment can make the optional eastern dock objective easier. Use Decatur to draw fire on land and keep Marines out of cannon range until the guards are engaged. The Corsair should not begin attacking the Philadelphia's dock before the force is ready; use a safe parallel position and complete rescue or treasure objectives first.
Set up the harbor defense
Before the defense starts, build Outposts near the end of the dock so their fire covers incoming ships. Keep the Falconet behind the Outposts to attack enemy vessels, and place Marines along the ramp to stop land forces. The players receive several Home City shipments at this transition, with an additional shipment possible after collecting the treasures. Sharpshooters and Infantry upgrades are valuable because many pirate waves contain Heavy Infantry. Send three Rowboats as an early shipment if the players want to attack the eastern docks; their stealth helps them pass patrols and their range supports the objective. Capturing the Fixed Gun earlier also allows the players to destroy the bridge explosives before the main defense sequence begins.
Manage land and naval attack waves
During the defense, keep ships close to the dock so patrolling Privateers do not pull them into an unfavorable fight. When a stronger enemy ship appears, kite it toward the Outposts and Falconet rather than pursuing it into open water. On land, use Decatur's flag to improve allied attacks and assign the Falconet to low-health units or enemy ships. Marines can handle Tribal Horsemen and Barbary Corsairs; Decatur's grenade and Marine bonus damage help remove Falconets before they deploy. The attack becomes more persistent around five minutes on the timer, so conserve units during the earlier waves and use shipments to reinforce the line. The mission rewards careful placement and target control more than an all-out ship attack.
Escape after the explosives are loaded
When the defense timer ends, the objective changes to escape with the Corsair. Load the surviving army into the ship, activate its flag, and sail back to the starting island. A captured Fixed Gun can open the shorter route by allowing the players to destroy the passage bridge. Do not leave Marines or the Falconet behind on the dock once the escape begins. The mission's sequence is designed around preserving transports and controlling the harbor: success depends on using the Corsair to enter and exit, clearing land guards in manageable groups, and keeping enough defenders alive to hold the loading period.
Coordinate responsibilities between players
The two players begin with matching ships and Marines, so divide tasks rather than sending both forces through the same narrow approach. One player can protect the Corsair and clear a shore route while the other scouts for prisoners, treasures, or the Fixed Gun. Agree on which player controls Decatur and the Falconet after the two forces meet, and avoid duplicating shipments that the defense needs in different places. Both players should keep at least one transport route open for the final escape. Cooperative timing matters most before the defense timer: optional objectives are easier when one player works on them while the other keeps the harbor approach safe.
A staged plan for Hard difficulty
Hard begins in Commerce Age rather than Fortress Age, so the players have a weaker initial technology and unit position. Preserve the starting ships while capturing the Corsair, use Rowboats and explosives to clear the first shore, then prioritize prisoners and the Fixed Gun before activating the long defense. Keep Decatur protected and let the Marines or Falconet remove guarded groups. During the timer, hold the ramp with Outposts, Marines, and the Falconet while ships kite enemy Privateers into the shore defenses. Save the Corsair as the exit transport and use the captured gun to shorten the escape.
Know which ships to preserve
The Sloops and Rowboats serve different purposes during the mission. Sloops can contest the escort and help defend the harbor, while Rowboats use their range and stealth for shore approaches, bridge clearing, and optional dock objectives. Preserve at least one Rowboat for the middle and late sections if the players want to complete the side objectives efficiently. The captured Corsair is the essential transport for the infiltration and final escape, so do not leave it exposed to the stronger patrol ships.
Co-op roles and extraction order
The co-op version preserves the same mission-critical order: disable the Mastico’s escort, seize the harbor entrance, then bring Mastico alongside the USS Philadelphia after clearing its guards. One player can maintain pressure on the harbor defenses while the other keeps the captured ship’s route clear; agree on who protects the channel before beginning the loading phase. The timed defense around the explosives is a commitment point, so complete the fixed-gun shortcut, crew rescue and eastern fleet objective first if they are part of the plan. Keep the frigates at the entrance available for extraction, and do not leave Mastico unattended while the Philadelphia is being prepared. The co-op setting changes coordination and force distribution, but it does not remove the requirement to return the corsair ship to the friendly frigates. Protect the escape route after demolition rather than treating the destruction of the Philadelphia as the end of the mission.
Keep a player with Mastico through the timed phase
In co-op, assign one player to guard the corsair ship while the other clears harbor defenses or completes an optional route. The Mastico is required first to reach the Philadelphia, remain safe while explosives are loaded, and return to the frigates. Coordinate the fixed-gun shortcut and crew rescue before starting that defense if they are part of the plan. A ship that is captured but left unattended can be lost before extraction, so keep an escort with it at every stage. The mission ends only when Mastico reaches the friendly frigates, not when the Philadelphia is prepared for destruction. Save enough naval support for the return across the harbor.