> For the complete documentation index, see [llms.txt](https://docs.truebit.io/v1docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.truebit.io/v1docs/getting-started/truebit-on-ethereum-structure.md).

# Truebit on Ethereum Structure

The verification game is testing the program ON-chain. But let’s remind ourselves of the true purpose of Truebit on Ethereum. Computational complexity is so high that programs cannot be run ON-chain and therefore we use Truebit on Ethereum. Therefore, a verification game cannot run the entire program code.

In fact, only one instruction line is used in a verification game. There will be a part of the program code where there is a discrepancy between the Solver and the Verifier. The instruction of that discrepancy point is used to verify who is right. For this, the Truebit on Ethereum contract implements a WebAssembly interpreter.

<figure><img src="https://1705716299-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNIJ0ssLBn8FjVyBhsqsw%2Fuploads%2FdcuCdZBSeduWu2ASObPC%2Fimage.png?alt=media&amp;token=9433ce4d-c6c3-4591-88cb-856e6d09d94a" alt=""><figcaption><p>Truebit Overview Diagram</p></figcaption></figure>