Regular-plus difficulty
Regular-plus difficulty or regs+ difficulty is a difficulty level between regular difficulty and nationals difficulty.
High School
In high-school quizbowl, regular-plus difficulty is generally defined by question sets like HFT and BHSAT, which seek to facilitate higher-level competition than regular-difficulty sets and better prepare teams for nationals. NAQT's Division II SCT sets, often used at high-school NAQT State Championships, are also considered regular-plus difficulty.
College
In collegiate quizbowl, regular-plus difficulty most often refers to sets like CMST and Terrapin Open that are harder than ACF Regionals and easier than ACF Nationals. It is usually equivalent to "Regionals-plus" difficulty, "pre-nationals" difficulty, and "3.5-dot" difficulty on Ophir's scale.