# Optimism proposes Super Root fault proofs and OPCM v8 upgrade

> New dispute games would use Super Roots. Permissionless chains would switch to game type 9; permissioned chains would use type 5, which resolves immediately for the defender while retaining the air-gap and Guardian blacklist.

- URL: https://riadefi.com/on-chain/2026-09-09-optimism-upgrade-20-super-root-dispute-games/
- Type: Upgrade or migration
- Stage: Proposed
- Evidence: confirmed
- Materiality: material
- Event date: 2026-09-09
- Version: 1, published 2026-09-15 (first published 2026-09-15)
- Follow-up: 2026-09-17
- Advisor-relevant: no
- Affects: Optimism canonical bridge (protocol)

## What happened

OP Labs submitted Upgrade 20 for governance consideration, proposing L1 contract changes to fault proofs and the upgrade manager.

## What changed

New dispute games would use Super Roots. Permissionless chains would switch to game type 9; permissioned chains would use type 5, which resolves immediately for the defender while retaining the air-gap and Guardian blacklist.

## What did not change

The proposal does not enable interoperability or require an L2 hardfork. Previously submitted withdrawal proofs and existing games remain supported under the proposed design.

## Confirmed

- The proposal includes OPCM v8 upgrade-path enforcement and SystemConfig cleanup.
- It targets Sepolia execution on September 17 and mainnet execution on September 24, subject to approval and testing.

## Still open

- Governance approval, completed rehearsals, signatures and actual execution are unverified.
- Operational readiness of withdrawal tooling and fault-proof services requires review.

## What it means for an advisor

- Review the Optimism bridge memo's dispute-game, upgrade-authority and withdrawal-tooling assumptions before the planned mainnet cutover.
- Do not treat the permissioned-game design as proof that OP Mainnet's withdrawal challenge period has already been bypassed.

## Sources

1. [Upgrade 20 - Super Root Dispute Games & OPCM v8.0.0](https://gov.optimism.io/t/upgrade-20-super-root-dispute-games-opcm-v8-0-0/10856) · Optimism governance — OP Labs proposal · 2026-09-09


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Published by Ketju Research on RIADeFi (https://riadefi.com). Educational research for financial professionals; not investment, legal, tax, or compliance advice.