Project MARS is looking for volunteers in the Providence area ages 21-50. Eligible participants must be current alcohol drinkers and cannabis users to participate in a confidential research study on the effects of cannabis and alcohol at Brown University. Participants will complete in-person study sessions and daily surveys in a phone app. Receive up to $572 by completing the study. Follow the link to complete the initial online screening: https://brown.co1.qualtrics.com/jfe/form/SV_d51KQQ3aHHreI3Y?SRC=rcra Call 401-863-6688 or email ProjectMARS@brown.edu with any questions. Study Protocol # 2022003195