Table 2. Type of game core drives and game components used in the included studies (N=26).

Game core drives		Studies, n (%)
Developmentandaccomplishment		11 (42)
	Challenge	9 (35)
	Bottom line	1 (4)
	Leaderboard	1 (4)
Empowerment creativityandfeedback		6 (23)
	Tailored message	2 (8)
	Online timely feedback	2 (8)
	Progress bar	2 (8)
Ownershipandpossession		17 (65)
	Points	10 (38)
	Money	1 (4)
	In-game currency	2 (8)
	Badges	5 (19)
Social influenceandrelatedness		13 (50)
	Mentorship/character narrative	6 (23)
	Discussion forum	6 (23)
	Allegiance	1 (4)
Unpredictabilityandcuriosity		3 (12)
	Unpredictable incentives	2 (8)
	Gumball/bonus draws	2 (8)