Build Levels
Number indicating a technology level, higher being more sophisticated. A scenario has a build level which determines what units and buildings the player has access to. For singleplayer scenarios this corresponds to the technology that would be available when this many scenarios into the campaign. The tech levels are different for multiplayer. For both single and multi-player, level 99 and above should be considered off-limits as it allows the construction of things that aren't really intended to be built, such as the hospital and bio research lab, which don't do anything and cause graphical bugs in the sidebar. For the full tech tree, use build level 98. Note that the AI ignores tech level and prerequisite building requirements in singleplayer.