You're talking about endless caves, right? First, upgrade weapons and armor to full level, and develop light firearms and drills. Equipped with the most advanced armor. Map development to 90%, rocket launcher reward. Players are basically as high as possible, and they will be upgraded if they can't pass the office first. Skills are above level 3. In the early stage, let residents with high physical strength learn appropriate skills and upgrade them, otherwise their skills will not rise. Team configuration: the front 1 platoon should be absolutely physical. An athlete who uses violence or defensive skills. The second platoon used powerful shooting to restore their physical skills, rocket launchers and pistols. The second platoon uses snipers. Next, it depends on your luck in fighting. It will be easy to start with more skills. If not, you can only upgrade the player.