Players can construct buildings anywhere in Genesis. Unlike Second Life, there is no real-world fee for buying land. Players can attempt to claim any land they want, although other players can take it over, or steal from their property. Political systems are in place to help protect players' lands; players can buy land in a city with well-guarded walls, for example. Players build structures using a variety of geometric primitives. Structures can be built anywhere; if a large enough tree is found, it is possible to hollow it out and build a house inside of it. Alternatively, a house can be built around a tree, high above the ground (similar to an Ewok village). It is possible to hollow out terrain - unlike most games where it is only possible to raise and lower the altitude of the terrain, the Genesis engine allows players to actually dig underground tunnels. Using this, players can dig out mines, hollow out mountains to make dungeons, and so forth.
Structures, like items, have a quality rating based on the quality of the resources they are built out of and the quality of the construction work performed. Vandalism and complete destruction of buildings are possible, as is theft of items inside, but there are safeguards in the game (see Religion or Player Voting). The penalty for such actions discourages many players from doing so. Aside from this, there are other measures that can be taken; for example, setting up traps and security systems in a house, as well as residing within a city regularly patrolled by guards. Players can also post a reward for the return of stolen goods and the capture of the thief. In other words, players can protect their houses in a very similar manner to how they can in the real world, with logging out similar to going on vacation. Every piece of property, whether an item or a house, carries a signature with it that determines who it belongs to.