I kept hearing people talk about a "secret room" at the Dam Battlegrounds, so I finally went looking for it, and yeah, the Controlled Access Zone is real. It sits off to the southwest of the Power Generation Complex, and the entrance is easy to blow past when you're focused on footsteps and ARC patrol routes. Most runs, you end up slipping in from the lower walkways or grabbing a ladder under the dam's ribs, then praying nobody's watching your back. If you're trying to plan the run properly, it helps to think about what you might need ahead of time, like ARC Raiders Items that'll keep you moving when the area turns into a mess.

Getting the Place to Wake Up

Inside, the first thing you'll notice is the heavy vault door with four dead indicator lights. It looks simple. It isn't. Before anyone starts shouting callouts, you've got to power the zone, and that means finding a Fuel Cell down on the lower decks. It's bulky, it slows you down, and it always feels like the game spawns an extra machine right when you pick it up. You haul it upstairs, slot it into a terminal, and only then do things come alive enough to access the room that holds the first button.

The Four-Button Timing Trap

This is the bit that turns squads into chaos. There are four buttons spread around the area, and they're not politely placed in a neat line. One might be on a catwalk, another tucked behind pipes, another up a short stairwell where sound carries way too far. The trick is timing: they need to be pressed almost together, close enough that it feels like the game's judging your reflexes and your teamwork at the same time. Call it out, count it down, whatever works, but if one person hesitates or gets spooked and hits early, the whole sequence resets. I've seen people brag about doing it with three by sprinting like lunatics, but for most groups it's a clean four-person play, especially if you've got randoms who don't share your sense of urgency.

Fixing the Panel and Cashing In

When the door finally opens, don't relax yet, because the next roadblock is a busted control panel that wants parts. Usually it's Metal Parts and an Industrial Battery, but sometimes it asks for weirder stuff like ARC Power Cells or a Leaper Pulse Unit, and that's when the room stops being "puzzle" and starts being "panic." If you didn't bring the right kit, you're scavenging nearby shelves and corners while listening for rival squads rotating in. The payoff can be huge—high-tier weapon crates and gear that can swing an entire raid—but the noise and the time spent standing still are basically an invitation, so it's smart to get in, sort fast, and get out. If you're short on essentials or trying to gear up without endless grinding, a lot of players use U4GM to pick up currency or items and keep their loadouts raid-ready before taking on risky spots like this.