Access the official 2026 King of the Hammers Rulebook online or download the PDF, along with technical documents and reference materials for Ultra4 USA competition.

Whether you’re building a vehicle, preparing for technical inspection or confirming a rule before race day, this is the official source for current regulations and supporting resources.

The online Rulebook makes it easier to find and reference the information you need while preserving the official wording of the 2026 Rulebook. Search by keyword, rule number, section or topic, browse every major section on its own page and link directly to individual rules and subsections. Built-in navigation and cross-references help you move through the Rulebook quickly on desktop or mobile.

The online Rulebook complements the downloadable PDF and is intended to make the official rules easier to search, reference and share.

Direct rule and tech questions to Tech@KingoftheHammers.com.

Please cite the rule in question with the page and item number from the Rulebook when emailing.

Used during tech inspections:

SFI rated head and neck restraints are required for all classes:

Direct rule and tech questions to Tech@KingoftheHammers.com.

Please cite the rule in question with the page and item number from the Rulebook when emailing.