Game Theory with ink!

An ink! tool for playing and researching games based on the field of "Game Theory" by using smart contracts.

This repo contains an implementation of some games within the Game Theory field.

One example of games in the field of game-theory is called "Prisoner's Dilemma" and here's a video from Youtube explaining the game's logic.

Current deployments on Shibuya Testnet

• public good: WiSYijQ7QyTvpt27CuqyoyGgi6Z3okXeuEt9JeB9mjcAdgG
• rock paper scissors: XeYM2p1KSq9z3daXwfaw41ZKZLPbJGdaBdghsrfb3kPNMBm
• dictator: randomness extension not currently supported on Shibuya.

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Explanation & Demo Video

Only a couple of games are currently implemented, deployable (tested on Shibuya) and playable from the list linked above, however, the implementation is done such that it follows a standardized set of traits (see ./logics/traits directory) defined within the reusable (across contracts) code such as type and trait definitions. More details in the Project Components section.

Taking such an approach means more games can be easily added to extend this project beyond the current hackathon submission.

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Motivation

Open-source software such as oTree, a behavioural-research platform, is often used to create games in order to simulate, with students or participants, stakes seen in real-life economics. Data from such simulations is then utilized in research papers or case-studies.

This motivates us to create a decentralized version of such a platform. The benefit of using blockchain for such a purpose is the following:

• Transparency and Trust of data quality and authenticity
• High Availability
• (potentially) Incentive-driven participation of players

Sources for economics research can vary and be equally valid. Could blockchain and lightweight yet economically motivated games introduce a fun way to contribute to this goal?

Another motivation is the exploration of !ink smart contracts functionality for basic game dynamics development.

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Overview

Logic Organization

Architecture & Components

1. Traits: the traits crate defines the behaviours which every game must provide as well as common types.

   • There 3 trait-defintions which specify the methods needed by each game. Lifecycle (game play methods), Basic (simple getters/setters) and Admin (admin-level methods). See traits module.
   • Common types include GameError, GameConfigs and other relevant data types. See types module.

2. Games: the games are !ink smart contracts which implement a subset or all the traits mentioned above.

   • Each instance of a game contract represents a single game play.
   • To play the game again, a new instance must be launched.
   • The contract should terminate once the game is completed and the final round's winnings are issued.

3. [post hackathon] Router: the games_router create defines a generic contract which the UI will invoke when launching new games as well as when having high-level interactions with the games' contracts.

   • It does not contain game specific code.
   • It is extensible to allow future games to be added.

4. [post hackathon] Typescript/React UI a. Add event indexing and lookup b. Add Admin / Analytics dashboard c. Add ability to connect using a wallet (see use-inkathon)

Game Lifecycle Flow

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Getting Started

Note: please use the nightly-2023-02-07 cargo toolchain channel. See Cargo.toml

Testing

Simply run cargo test to run tests of all the crates / packages.

To run a specific contract's tests, use the -p (or --package) flag, for example:

cargo test -p public_good

or

cargo test -p rock_paper_scissors

or

alternatively cd into that contract's directory and run cargo test within the package code.

Building Contracts

Since this is a workspace, each contract currently needs to be built independently into WASM / ABI.

Use the following command to a build a contract:

cargo contract build --release --manifest-path contracts/SOME_CONTRACT_FOLDER/Cargo.toml

or this to build all of them:

sh build-all.sh

Deploying Contracts

Contracts can be deployed on any Substrate chain which supports smart contract functionality via !ink, however, some games' contracts require certain chain-extensions in order to operate correctly.

For example, the Dictator game requires a function which generates a random value. This functionality is available in the Randomness Pallet and can be made accessible by using the chain-extensions feature in !ink and add some relevant code in the Runtime to handle calls from smart contracts.

Note: The corresponding Runtime code which handles getting the random value from the pallet is added into a forked version of "Swanky Node".

See the extension-specific code added to the forked Swanky Node Repo for reference.

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Next Steps

• Create UI for Game Theory experiments: #44
• Use shared events: #33
• Move completely to OpenBrush
• Enable Upgradeability: #34
• Use Mappings instead of Vector of Tuple: #10

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Contributors

• Faisal A.
• Arthur F. M.