Regular-plus difficulty or regs+ difficulty is a term for the difficulty level between regular difficulty and nationals difficulty. The ambiguity on what constitutes "regular" difficulty has contributed to a corresponding confusion about where the boundaries of "regular-plus" lie.
The use of Regionals difficulty as an equivalent to regular difficulty means that regular-plus is also called Regionals-plus.
In high-school quizbowl, regular-plus difficulty is generally defined by question sets like HFT and BHSAT, which are intentionally more difficult that IS sets to facilitate higher-level competition 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.
In collegiate quizbowl, regular-plus difficulty was previously used to tournaments intermediate in difficulty between ACF Regionals and ACF Nationals, like 2015 VCU Open. The number of tournaments that use this label has diminished in recent years, with the "nationals-minus" tournament taking its place. "3.5 dots" on the college quiz bowl calendar's difficulty scale is sometimes used to refer to tournaments at this difficulty; however, this is not a recommended use of the difficulty scale, which intends each dot value to represent tournaments appropriate for a subset of the audience and not any specific difficulty.