Board Thread:General Discussion/@comment-65.189.51.64-20180808161057/@comment-35175794-20180814135341

Yes you can use on the decreases energy the game will tell you if you if are using two of the same. It won't even let you use two that do the same. You should be good to go. If you hire friends as you go you can level stack them as well. Each friend gives you a boost of some kind, either, more money, more XP, help with finding things or less energy per room. Just be sure and hire them only once each and do not energize them or the game will take your rubies.