Three instruments are available:

• The Adult Playfulness Trait Scale (APTS), A 19-item self-report scale that measures the disposition to engage in playful behavior (Shen et al., 2014a, b), a copy of the APTS-English version is provided here. Also see the Turkish (Yurt et al., 2016) and Chinese (Shen et al., 2021) version.
• The Playful State Scale (PSS): A 16-item self-report scale that measures the quality of playful engagement during play (Shen, 2020)
• The Psychological Situations for Play Scale (PS2): A 6-item self-report scale that measures two key dimensions of psychologically meaningful conditions that activate and support play (Shen, 2020). 

Instruments in other languages:
​The APTS has been and is being translated into a number of languages, including Korean, Chinese, Hebrew, Arabic, Persian, Indonesian, and Turkish. If you are looking to use the APTS in another language, please search journals in that language to see if it already exists (e.g., the Turkish version in Yurt, Keleş, & Koğar, 2016).
For those who are interested in translating the APTS into a different language, you may find this annotated bibliography useful. It offers a list of readings about guidelines for translating surveys in cross-cultural research. The document was prepared by the Measurement and Methods Core of the Center for Aging in Diverse Communities at the University of California San Francisco.