---
title: "Four Steps to Creating Effective Game Day Tests"
description: "Game Day tests deliberately trigger failure modes in production systems and examine whether automated behavior and human response match expectations. Shopify frames the practice as preparation for outages that can arise despite code checks, reviews, and other safeguards. The method starts by inventorying possible failures, then selecting scenarios by impact and simulation difficulty rather than estimated likelihood. Each scenario becomes a controlled experiment with prerequisites, testable hypotheses, expected alerts and downstream behavior, plus recovery steps recorded in a spreadsheet. During execution, teams track results, communication, and work distribution; afterward they fix gaps, review coordination, update response guidelines, and rerun tests to verify changes, with periodic testing keeping systems and people prepared."
---

# Four Steps to Creating Effective Game Day Tests

[Shopify](https://yomu.fyi/company/shopify) · 2023-10-18 · Nov 12, 2019

**Type:** Tutorial

## Summary

Game Day tests deliberately trigger failure modes in production systems and examine whether automated behavior and human response match expectations. Shopify frames the practice as preparation for outages that can arise despite code checks, reviews, and other safeguards. The method starts by inventorying possible failures, then selecting scenarios by impact and simulation difficulty rather than estimated likelihood. Each scenario becomes a controlled experiment with prerequisites, testable hypotheses, expected alerts and downstream behavior, plus recovery steps recorded in a spreadsheet. During execution, teams track results, communication, and work distribution; afterward they fix gaps, review coordination, update response guidelines, and rerun tests to verify changes, with periodic testing keeping systems and people prepared.

## Context

Game Day tests prepare teams to respond quickly and coordinate effectively when production systems fail in unexpected ways, including incidents caused by forces outside their control. The practice addresses both system behavior and human coordination under pressure.

## Approach / What changed

The four-step method inventories potential failures, selects scenarios by impact and simulation difficulty, expresses expected behavior as controlled experiments, records prerequisites and recovery steps, evaluates team communication during execution, and addresses uncovered gaps through fixes, follow-up discussion, updated guidelines, and repeat testing.

## Takeaways

- Select Game Day scenarios by estimated impact and the difficulty of reasonably simulating them, rather than by how likely the failures seem; perfect-storm incidents may depend on underestimated failure points.
- Record each experiment’s prerequisite steps, hypotheses, expected behaviors, observed results, and system-restoration steps in a spreadsheet.
- Evaluate team communication and work distribution alongside automated responses, then fix gaps and rerun the Game Day test to verify the new behavior.

**Tags:** [Incident Response](https://yomu.fyi/topic/incident-response), [Reliability](https://yomu.fyi/topic/reliability), [Testing](https://yomu.fyi/topic/testing)

- Source: [Shopify](https://shopify.engineering/four-steps-creating-effective-game-day-tests)
- Source URL: https://shopify.engineering/four-steps-creating-effective-game-day-tests
- Ingested by Yomu: 2026-08-31T01:13:35.313Z

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