Old Uncle Geekly is trying a new trick. This week’s favorite game mechanic comes from video games, Fallout Shelter in particular.

On the surface Fallout Shelter shares a lot of commonalities with other free-to-play games/apps like Clash of Clans. Players download it for free and it offers in game purchases for players to get better at the game faster than they would by investing only time. But the one thing that separates this game from other free-to-play games is also the one thing that makes it uniquely Bethesda. The player competes against the game, not other players.

When one logs off of Clash of Clans or a Clash of Clans clone, logging back in allows them to see what other players did to their defenses while they were offline. This sometimes leads to players paying for repairs (tying up a worker to repair counts as “paying”) and regrouping. There’s usually a tournament included in games of this ilk and only the best players—or the ones willing to pay to win—fair well in these tournaments. There’s a reason people scoff at these games as “pay to win.” The only way to get ahead in a game like that is to pay something. Fallout Shelter eliminates that style of play.

Sure, you could pay to get better things faster in the game, but the only player you can see is yourself. Fallout Shelter allows players to do things at their own pace. It doesn’t apply the pressure of a tournament.

Now I’m not saying that I don’t enjoy the occasional competitive free-to-play game, but Fallout Shelter’s brand of leveling up your vault dwellers how you see fit and sending them out on missions or exploring the wastes fit with Bethesda’s gaming catalogue. This isn’t just a free-to-play game. This is a Bethesda free-to-play game.

Is it for everyone? No. Did some gamers download it because they saw the word Fallout? Of course. Am I a Bethesda fanboy? You know it. But it’s the Bethesda open-world RPG flavor of Fallout Shelter that makes me interested in the game, and I hope other free-to-play games follow suit.

Player versus environment may be my favorite game mechanic, but I promised at least one more mechanism and here it goes. When Fallout Shelter first hit the app store, it bragged about players not having to wait for construction. Again, games like Clash of Clans have players build items and then they must wait real-world minutes or even hours for those items to be constructed. It’s a time waster. Well, you could pay gems (which end up being real-world money) to instantly build an item, but that ruins the idea of “free-to-play.” Fallout Shelter doesn’t have players wait for construction. If you have the resources, you build the room within your vault immediately.

While immediate construction was a huge selling point for the game, it opened new game mechanisms: push your luck and managing vault dwellers. Players didn’t wait on construction, they waited on their rooms to produce resources like food and water that their people needed.

The more dwellers one sent to a room, the faster that room produced the resource. This is a clever way of adding yet another resource (workers) to the game system. One could also “push their luck” by rushing production in a room. If one succeeds, the game gives them more resources. If the rush fails, the game generates some crisis (radroaches, a room fire, or deathclaws) the player must resolve.

It’s subtle, but the push your luck and managing vault dwellers mechanisms are excellent additions. Come to think of it, they may be just as important as making Fallout Shelter player versus environment.

I guess I had more than one favorite mechanism for Fallout Shelter after all. I’m sure I got lost somewhere while I searched the wastes. If I did, slap upside the head with a radscorpion barb. Or you could always say something in the comments.