The oldest and hardest goal in the blockchain gaming industry has been to develop a completely decentralized game, a persistent online world with no server. Early experiments such as Huntercoin and Motocoin proved epic, but were held back from the mainstream by installation difficulty, hardware requirements, and the inability to deal with artificial intelligence.
The community has continued trying to place the virtual world on the blockchain, however. Part of the appeal is eliminating server downtime; other reasons include hosting cost reduction and improved security against hackers. They also come with the standard benefits of token economics, true ownership and provable fairness.
Most exciting, however, is the potential for decentralized autonomous worlds, with no mods or admins. This makes them feel more alive—organic virtual worlds that evolve naturally and create their own stories. Every battle is significant, the elite are players, and the developers can’t interfere without the consensus of the community.
The history of decentralized MMOs contains some fascinating tales. The most dramatic was that of Huntercoin, replete with epic battles and a mysterious villain. Unfortunately, bots plagued the land and players failed to defend it, requiring a hard fork to save them. Drama was constant and ongoing, including the death of a founding developer.
First attempts to build a decentralized MMO on Ethereum ran into scaling issues. A game of Chess, for example, is easy to calculate with a CPU, but so expensive to compute on-chain that Ethereum’s virtual machine can’t process the checkmate, at all. A later experiment replicating Battleship demonstrated the feasibility of using state channels, similar to the Lightning Network.
The most advanced platform for this is XAYA. The tools for implementing “game channels” are built into the protocol, as well as an additional scaling innovation called “ephemeral timestamps.” They also use what are known as “atomic transactions” to facility decentralized trade amongst their community, which includes the games Xayaships, Taurion, Soccer Manager Elite and Treat Fighter.
Others continue to make progress on Ethereum, especially in the realm of empire-building games. In Cryptowars, players trade and battle across medieval realms; in Orbiter 8, they conquer and rule entire planets. Although sticking with turn-based gameplay has helped limit scalability issues, they are still experimenting with off-chain solutions such as Loom and Plasma.
Exciting progress has been made to improve the scalability of decentralized MMOs. The lead XAYA developer hypothesized in one paper for a scientific journal that blockchain sharding—where the blockchain is broken up into pieces, each of which are held by only a few players—could be used to scale massive multiplayer online games. Sharding is also developing rapidly on Ethereum to alleviate its general scalability issues.
Artificial intelligence remains a thorn in the community’s side, however. One issue has been how to implement NPCs in decentralized worlds; the code for even very simple ones doesn’t fit on the blockchain. Platforms like XAYA can solve this by relying on players to store AI code locally, using consensus to decide NPC behavior. Sharding would limit the number of players required to participate.
More difficult is the opposite problem: how to prevent artificial intelligence in games when they’re unwanted. When human mining, the rewards incentivize the development of bots to earn cryptocurrency and items; this can easily disturb the balance of a game. Blockchains relying on proof-of-play—where the winners of matches get to mine the blocks—also become susceptible to 51% attacks.
One solution is easy: a semi-centralized set-up. Trusted third parties verify the identity of private key holders and monitor their in-game activity. The Holy Grail, however, is a decentralized Turing Test: a trial to determine whether or not a person is real or simulated, automated on a peer-to-peer network without a central authority.