**1. Introduction**

In 2008, the white paper for peer-to-peer payments was published by Satoshi-Nakamoto [1]. Various blockchains have been developed since then and are always discussed as *financial innovation*. Besides the FinTech aspect, however, there are also other possible purposes.

As Vitalik Buterin described in 2014, blockchains can also serve as decentralized autonomous organizations (DAOs) [2]. DAO refers to an association of like-minded members who control and manage it. A DAO is based on a set of rules in which the basic rules of the organization and its financial management are defined. Once this set of rules—for example, in the form of a smart contract via a blockchain—has been made accessible to members, these publicly visible rules can no longer be changed, except by a vote of the members [2].

A DAO is, therefore, not controlled by a central authority, but by the member collective itself. It can, for example, be a donation organization in which the donors can vote on to whom the collected sum should be donated. Voting can be viewed in a similar way to stock corporations. The weighting of the votes depends on the amount of money previously paid in. The voting can be executed via the so-called governance tokens [3].

The goal of this thesis is the investigation and implementation of a multiplayer game based on the DAO principle. The main idea is that a collective of players makes decisions together. Using the example of "Connect Four," in which two teams with any number of players compete against each other, the next move of each team is decided democratically by voting using governance tokens.

To add excitement to the game, the winning team should be rewarded with the deposits (governance tokens) of the opposing team at the end of a match. A key aspect to consider when implementing such a community game is that a game is chosen where all the moves can be made public and there is no need for additional encryption of data on the blockchain. This is deliberately chosen so that the focus of this work is only on the implementation of the community game and more complex problems regarding data encryption are avoided, which could affect the implementation of the project in terms of time or even prevent it. The game "Connect Four" fulfills these requirements and is, therefore, a suitable candidate for this elaboration. Another challenge is to implement the game in a completely decentralized way so that all the calculations, data transformations, and game moves can be publicly viewed via the blockchain at any time, thus ruling out any manipulation of the game flow. Another key aspect to consider when implementing such a community game is whether both the specific nature of decision-making and the use of a blockchain can lead to unforeseen problems in the game flow for the participating players. Therefore, the research question can be described as follows:

*RQ: What difficulties arise with regard to the usability of the game due to the use of the DAO principle and how do they affect the players' experience?*

To answer this question, a *webapp* will be developed, which implements the multiplayer game and communicates with the blockchain. Blockchain applications offer the advantage of creating pseudoanonymity between participants. More precisely, this means that although all the transactions and rules are visible within the blockchain, the transaction partners are anonymized by unique keys [1]. In this way, a blockchain offers a high level of transparency and, at the same time, a high level of anonymity [4].

This work is divided into four parts. In addition to related work and the architecture of the decentralized application (in short: dApp), the implementation and a subsequent evaluation are described. There, the usability of the application is evaluated and discussed by using a questionnaire. A conclusion and an outlook conclude this work.
