Bet on Friendship (Czech: Prvok, Šampón, Tečka a Karel, literally Element, Shampoo, Dot and Karel) is a 2021 Czech Comedy film by director Patrik Hartl. It is an adaptation of Hartl's novel by the same name.^[3]

You can help expand this article with text translated from the corresponding article in Czech. (February 2024) Click [show] for important translation instructions. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Czech Wikipedia article at [[:cs:Prvok, Šampón, Tečka a Karel]]; see its history for attribution. You may also add the template {{Translated|cs|Prvok, Šampón, Tečka a Karel}} to the talk page. For more guidance, see Wikipedia:Translation.

• Martin Pechlát as Element
• David Švehlík as Shampoo
• Hynek Čermák as Dot
• Martin Hofmann as Karel
• Zuzana Norisová as Lubica
• Daniela Kolářová as Dot's mother
• Jana Kolesárová as Klára
• Kristýna Boková as Saša
• Barbora Poláková as Shampoo's assistant
• Petra Polnišová as Jarmila
• Martina Hekerová as Vitamine miss
• Hana Vagnerová as Karolína
• Martin Sitta as Dot's colleague
• Eva Josefíková as Secretary in Karel's company
• Tomáš Maštalír as Max
• Ľuboš Kostelný as Gába