

As such, these maps were big, and utilized vehicles to traverse the world. Teams would defend and conquer this territory using buildings and their classes' various abilities. The game revolved around controlling territory of the map known as "Control Zones", which houses Vehicle Bays and Resource Zones that can be utilized by the controlling game. The Aliens don't require power and as such, buildings are more expensive. The teams have two key differences the Humans require power for their buildings to function, and as such have objects that cost less. There are various ways for players to acquire chunks of Resources, including killing enemies, destroying enemy objects, or collecting from a Resource Pump. Resources are chunks that can be picked up by players, which are then added to the Resource bank of their team. Gameplay is largely based around the collection of "Resources," called "Jojierium". The average Invasion game consists of two teams - the Humans and the Aliens, with a game split up between three 15-minute rounds known as Acts. The Orders feature originated from Brotherhood of Arms and is still one of the many things from that point of development to survive up until Invasion. The Tactical View allowed players to give orders to other teammates, witness the battlefield from above, and various other things. The Commander class is still present in Invasion, but all classes can utilize it as it morphied into a feature called Tactical View. Of course, gameplay was also shaped by the theme and art style which added in key differences. As such, it's safe to say the only thing that ever changed for Team Fortress 2 was gameplay objectives, art style, and theme. The Officer class from Brotherhood of Arms was removed, and instead converted into the Rallyflag and his morale effects became the Adrenalin power-up.
#TF2 ALIEN INVASION CODE#
such as tf_accuracy.cpp, which was removed because it was deemed too complicated and could be done in an easier way according to code comments. Evidence of this can be found in the 2003 leak's Source Code, in which some leftover Brotherhood of Arms code can be found. Invasion stems from none other than the Brotherhood of Arms phase of development.

Originally being less World War I inspired with the Humans, and more retro-steampunk in design, with the Aliens looking less advanced and more primitive than seen in later concepts. Shortly following this, Moby Francke joined Valve and designed the War of the Worlds-inspired Invasion pre-release Team Fortress 2 designs (and, later, the release designs). At some point, the game became more focused on territory control and introduced Resources for the first time. Over time, this changed greatly when Aliens were added, and the futuristic sci-fi theme was scrapped to make way for a futuristic Humans vs Aliens, with the designs being largely Roman-inspired, despite still being futuristic. Early in Invasion's life, the game was much like Brotherhood of Arms in terms of classes and gameplay, but with a futuristic sci-fi theme.
