D20

D20, D-20 or d20 may refer to:

Arts, entertainment, and media

• d20, a polyhedral die commonly used in role-playing games
• d20 System, a role-playing game system published by Wizards of the Coast
• Arriflex D-20, a film-style digital high definition movie camera
• D-20, a version of the Roland D-50 synthesizer
• Dimension 20, a tabletop role-playing game show made by CollegeHumor
• Queen's Gambit Accepted, Encyclopaedia of Chess Openings code

Military

• 152 mm gun-howitzer D-20, a Soviet artillery piece
• ARA Almirante Brown (D-20), a destroyer that served with the Argentine Navy between 1961 and 1982
• Brazilian destroyer escort Baependi (D20), a destroyer escort that served with the Brazilian Navy between 1944 and 1975
• Greek destroyer Doxa (D20), a destroyer that served with the Royal Hellenic Navy between 1951 and 1972
• HMS Fife (D20), a Royal Navy guided missile destroyer launched in 1964 and decommissioned in 1987

Science

• D20, a diffractometer located at Institut Laue–Langevin used in neutron research
• Heavy water, or deuterium oxide (D₂O or ²H₂O)

Vehicles and transport

• D20 road (Croatia), a state road
• Aero Synergie Jodel D20, a French ultralight
• Chevrolet D-20, a pick-up truck made in Brazil and Argentina
• LNER D20, a class of British steam locomotives
• Senova D20, a subcompact car made by SAIC in China
• Soloviev D-20, a Soviet turbofan engine

Other

• Dublin 20, a Dublin, Ireland postal district
• 2020 Democratic National Convention, American political convention, branded as "D20"