While most real-time strategy games feature multiplayer modes that let you battle against one or several opponents in skirmish battles, few let you try to conquer a galaxy. That's one of the ideas behind the galactic conquest mode in Star Wars: Empire at War, the upcoming real-time strategy game from LucasArts and Petroglyph due out next month. Set in the original Star Wars trilogy, Empire at War will let you command the forces of the Rebel Alliance or the Galactic Empire as you attempt to conquer the galaxy, one planetary system at a time, in both single-player and multiplayer. We'll let Petroglyph's Chris Rubyor explain.

　　Time to queue up some John Williams music.

Galactic Conquest for Two

　　Multiplayer designer, Petroglyph

　　I've been in the industry for more than 10 years, and, because I'm a former Westwood Studios employee (one of many at Petroglyph), you can kind of say that real-time strategy gaming is in my blood. I'm responsible for overseeing the overall multiplayer game designs, online user interface, and multiplayer map layouts for Empire at War. For the next two diaries, we're giving you a peek into both of the game's multiplayer modes. The next diary will cover eight-player skirmish mode, but let's kick things off by discussing two-player galactic conquest. This mode mimics the single-player experience and allows two players (one rebel and one imperial) to compete against each other for control of the galaxy.

　　Compared to the more traditional real-time strategy combat found in skirmish mode, galactic conquest actually resembles the single-player experience. From day one, our biggest challenge for galactic conquest was figuring out how to make a sandbox real-time strategy environment fun for both players. Unlike traditional real-time strategy games, both players do not start out with bases to build from in a tactical scenario (ground- and space-based maps). Matter of fact, almost all building is done at the galactic level. It is up to the defender of a given planet to ensure that he has enough forces protecting ground and space structures in the event of an enemy invasion.

　　For months we experimented with features that you can tune and tweak. It seemed like no matter what we did, though, gameplay more or less felt the same. There was an attacker and defender; you go from point A to point B. Why do anything else? The harsh reality was we had designed traditional-style real-time strategy maps for a game environment that did not support traditional real-time strategy gameplay. So, we took a small, 10-planet galactic conquest scenario ("The Lines are Drawn") and overhauled the maps using themed battles from our universe's own history.

　　Success! Our redesign altered the experience enough to provide more unique challenges and tactics for both the attacker and defender. In addition, we tuned the weather system for each planet to be less forgiving. Some examples include sight ranges reduced by up to 70 percent during blizzards, rocket accuracy reduced by half during dust storms, and intense heat causing severe damage to unprotected infantry on volcanic worlds. We also added the ability for hover units to cross over vast areas of deep water to reach remote areas. As a final touch, we got crazy and tied the population cap to reinforcement points. This allowed us to adjust the difficulty and change up the units and tactics required to capture each planet.

　　It's like the Battle of Hoth, minus all the snow.

　　We were very happy with the results, but there was one final hurdle we had to overcome. There were 76 land and space tactical maps that we needed to overhaul. Keep in mind that these maps are also used in the single-player campaign, so we had to be careful not to break things too much. Based upon learning from our newly revamped version of "The Lines are Drawn," we got to work reviewing each and every map, outlining exactly what needed to be done. Over the course of three weeks, we did the impossible and adjusted terrain and base layouts to be more tactical and themed, arranged reinforcement points in more strategic locations, adjusted weather settings per planet, and tuned defensive areas on each map. We now have more than 80 maps that offer players a variety of challenges and tactics unique to Empire at War.

　　Being so close to ship now, multiplayer galactic conquest allows us to play through and test each and every map for balance and fun factor. Because it is much quicker than the single-player campaign, we can make map tweaks and test them in a fraction of the time. Of course, skirmish mode demands its own unique design. I'll discuss this further in the next designer diary.