• 2017-11-22 Hazard System v0.3 PDF — release post
  Attribution: Necropraxis Productions Hazard System v0.3 (2017)
  http://www.necropraxis.com/hazard-system/
• 2014-12-23 Hazard System v0.2 PDF — first public release; release post
  Attribution: Necropraxis Productions Hazard System v0.2 (2014)
  http://www.necropraxis.com/hazard-system/

The Hazard System is released under a Creative Commons Attribution 3.0 Unported license.