Use the same criteria the judges use.
Current rules
Read the Rule Book in Resources
Read the Contest Rule Book before you build
The current NHD Contest Rule Book took effect on June 22, 2020 and applies from Regional through National contest levels.
Evaluation
Historical Quality 80% · Clarity of Presentation 20%
Historical Quality uses the same core criteria across categories. Clarity of Presentation changes by category.
Official source: NHD Contest Rules & Evaluation.