Quoted from BallyKISS1978:
Sherlock Holmes is in the public domain, well most of Doyle’s stories and characters are. Some of the later Holmes stories are not in the public domain yet.
True but you can (and should) trademark Sherlock Holmes branded merchandise like pinball machines, which is different than the character being public domain.
Word Mark SHERLOCK HOLMES
Goods and Services IC 028. US 022 023 038 050. G & S: Pinball games; Pinball machines; Pinball machines; Pinball-type games
Standard Characters Claimed
Mark Drawing Code (4) STANDARD CHARACTER MARK
Serial Number 90242280
Filing Date October 8, 2020
Current Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) American Pinball Inc. CORPORATION ILLINOIS 500 S Hicks Rd, Suite 100 Palatine ILLINOIS 60067
Attorney of Record Steven Marsh
Type of Mark TRADEMARK
Live/Dead Indicator LIVE
Poker Run, Valkyries, Robin Hood, and their previous Sherlock Holmes filings from Jan 2019 are all dead but Sherlock Holmes was updated last October.