It was fusion power and the invention of faster-than-light travel that helped humanity settle the Inner Sphere. Provides a framework for runtime modifications of the contracts, encounters and other map logic. By default, RogueTech is a huge expansion to the sandbox-styled Career mode in BattleTech. Flashpoints are multi-part missions introduced with the Battletech: Flashpoint DLC.
Be warned that roguetech has a much bigger difficultly curve than vanilla, especially with the second lance, even more enemies will spawn. Go to the Manage Installation entry and then click Verify/Repair and follow the prompts. Now that you know the basics, it's time to get into the nuts and bolts of how to win a mission.