---
type: "term"
title: "Event Chain Length"
description: "The number of causal events between the initial incident (E1) and a regulatory trigger point (E3x)."
resource: "tlctc:term:event-chain-length"
tags:
  - "glossary"
---
# Event Chain Length

The number of causal events between the initial incident (E1) and a regulatory trigger point (E3x). Shorter chains mean compliance clocks start sooner. Example: NIS2 path (E1→E3b) = 2 events with 24h early warning requirement; GDPR path (E1→E2→E3a) = 3 events with 72h notification timeline. Understanding chain length helps CISOs structure incident response playbooks to meet multiple regulatory timelines from a single incident.