Skill development system is quite complex in this game, so in this chapter, we present a thorough explanation of this topic. After entering the Facilities tab, we can see a screen full of various information. Basically, to unlock a given skill, we have to have a Facility Building Ticket and then just select the appropriate building visible in the middle of the screen. It is easy to guess that we need 7 tickets to unlock all the skills (they are obtained when leveling up). After unlocking the skills, they land in our storage and they can be move onto free slots to be quickly use during battles. As for the upgrades, they are connected with Researchers, who can be obtained when leveling up or bought for gold (this option is available from level 15). When we have them, we can distribute various numbers of them to different buildings, which means to different skills so that they start working on it. The development consists of two parts. The first one are two features of a given skill, for example the amount of damage dealt, which we can develop to their maximum by adding 60 people to each. The second part are three special upgrades, which are use instead of the basic skill. In this case, we need a certain amount of Researchers, to unlock an upgrade just once. However, at the beginning, we can only choose one of them and the second one will be available after developing the two stats of the basic version to maximum (you need 120 Researchers in total). If your choices don't satisfy you, you can always buy a Reset Ticket.