Table 2.

Summary of findings–strategies.

Strategies	Reviews (Number of Studies)	N	Summary of Findings on		Recommendations
			Effectiveness	Implementation Conditions
Supply reduction strategies
1. Restricting gambling venues and licenses	Gainsbury, 2014; McMahon, 2019 (2); Tanner, 2017 (2); Williams, 2012 (11)	13	This is one of the most important strategies to reduce gambling supply. However, the quality of empirical research in this area should improve. Preliminary evidence suggests that the EGM caps is an ineffective strategy.	The limitations often last for a short time. Long-term policies should be implemented.	To evaluate long-term policies’ implementation.
2. Pricing and taxation	Gainsbury, 2014; Williams, 2012 (1)	1	This is considered an effective strategy to reduce the gambling supply.	Increasing the price of participating in the legal market may increase the attractiveness of illegal markets. Illegal markets need to be under control for a tax increase to be effective.
3. Limiting gambling venue hours of operation	Gainsbury, 2014; McMahhon, 2019 (4); Tanner, 2017 (4); Williams, 2012 (3)	6	This seems to have an impact on reducing gambling harms and risk factors.	The consistency of opening hours across sites and the compliance with the regulation within the local context are fundamental.	Further research is needed to determine effectiveness of mandatory shutdowns to identify the most effective length of time and time of day for shutdowns.
4. Legal age	Gainsbury, 2014; Williams, 2012 (8)	8	Prohibition of youth gambling seems successful in reducing gambling problems and requires adult involvement. Evidence shows the link between parental facilitation and increased gambling behaviors.	The implementation of this age limit is problematic. More controls and families’ sensibilization strategies are needed.
5. Limiting accessibility to gambling venues	Gainsbury, 2014; Williams, 2012 (8); Young & Tyler, 2008 (20)	27	This is a controversial strategy in literature, but it is considered potentially effective.	The efficacy of these actions is susceptible to contextual variations and factors related to interactions.	The interaction with other contextual factors should be considered.
Demand reduction strategies
6. Restricting advertising	Williams, 2012 (13)	13	It is reasonable to hypothesize that advertising contributes to a positive attitude about gambling, an increase in engagement when it is offered and to social acceptability.		Further research is needed to understand the impact of gambling advertising.
7. Information/awareness campaigns	Ariyabuddhiphongs, 2013 (2); Gainsbury, 2014; Livingstone et al., 2014 (2); Williams, 2012 (8)	12	They seem to raise awareness of the role of probability laws and skills in gambling, avoiding gambling fallacies. However, they are not associated with any decreases in actual gambling behavior. There is no evidence of effectiveness of venue signage. Specific campaigns targeted at parents may be effective in increasing awareness of the importance of restricting youth gambling.	More targeted campaigns should be developed. Parents are a potential target.
8. Educational interventions	Ariyabuddhiphongs, 2013 (3); Forsström, 2020 (9); Gainsbury, 2014; Grande-Gosende, 2020 (9); McMahon, 2019 (2); Matheson, 2018 (3); Williams, 2012 (21)	38	Most adult educational interventions had little impact on behaviors. Specific programs aimed at developing participants’ skills, change attitudes and restructure cognitive processes seem to be successful. An evaluation of RGICs showed that visitors appeared to modify misconceptions but did not have any impact on gambling behavior. PNF or PFI is considered a potentially effective, low-cost and easily disseminated strategy.	It is important to involve professionals with close relationship with participants. The PNF or PFI implementation should be cautious because it may cause a “boomerang effect” when targeting low-frequency gamblers.	To develop and evaluate new adult educational programs and parent training.
Risk reduction strategies
9. Restricting access to cash	Livingstone, 2014 (1); McMahon, 2019 (2); Tanner, 2017 (2); Williams, 2012 (7)	9	ATM removal in the vicinity of gambling venues can be considered as a moderately effective strategy. Reviews identify a lack of empirical research.	Other cash sources are not considered.	Additional research about its effectiveness is needed. Other cash sources should be considered.
10. Placing gambling venues away from vulnerable populations	Williams, 2012 (5); Young and Tyler 2008 (11)	16	This has good empirical support.	A clear definition of vulnerable populations is necessary.
11. Ambient natural lighting	Williams, 2012 (4)	4	The lack of lighting and other design elements seems to promote gambling behavior mainly among current gamblers.	No information about different levels of light is available.	Additional research is needed.
12. Clocks and time awareness	Drawson, 2017 (2); Ladouceur, 2017 (2); Tanner, 2017 (2); Williams, 2012 (3)	4	Most of the studies are focused on on-screen clocks. Few studies focus on room clocks. It does not seem effective in reducing session length or expenditure.		Other strategies to facilitate time awareness should be investigated because time awareness can have a positive influence.
13. Machine location	Matheson, 2018 (2); Williams, 2012 (4)	5	There is conflicting evidence about this strategy but, overall, reviews suggest this is an efficient way to counteract gambling.		Both visibility and isolation effects should be considered.
14. Smoking bans/restrictions	McMahon, 2019 (2); Tanner, 2017 (2); Williams, 2012 (9)	11	This is considered as one of the most effective strategies.
15. Alcohol bans/restrictions	Williams, 2012 (10)	10	This has significant potential as a harm minimization strategy.		Additional research about its effectiveness is needed.
Harm reduction strategies
16. Gambling venue employee training	Ariyabuddhiphongs, 2013 (3); Beckett, 2020 (22); Gainsbury, 2014; Ladouceur, 2017 (3); Matheson, 2018 (5); Williams, 2012 (12)	31	Staff training programs are effective in changing staff members’ knowledge, attitudes, and self-confidence. However, they fail in promoting a proactive strategy and in facilitating intervention with some gamblers. Some training interventions have a short-term effect if not supported by the different stakeholders involved. There is insufficient evidence about effects in customers.	The main target is problematic gamblers, but all gamblers should be considered to encourage responsible behaviors. Behavioral skills training is necessary. Stakeholders’ involvement improves effectiveness.	More research about design, implementation and evaluation of employee training is needed. Training aimed at developing staff members’ behavioral skills should be designed.
17. Test and screening	Gainsbury, 2014; Livingstone, 2014 (2); Matheson, 2018 (1)	3	This is most likely effective.	Many barriers intervene: lack of time, skills, motivation, and organizational factors. These interventions are more effective when combined with specific training.	Additional research about the implementation is needed.
18. Helplines and care services information	Livingstone, 2014 (2); Williams, 2012 (4)	6	Results are inconsistent.		More studies are needed.
19. Precommitment	Kotter, 2019 (19); Ladouceur, 2012 17); Ladouceur, 2017 (5); Livingstone, 2014 (15); McMahon, 2019 (13); Matheson, 2018 (7); Williams, 2012 (11)	47	A conclusive statement on the effectiveness of pre-precommitment cannot yet be offered because of methodological problems, implementation discrepancy and inconsistent results.	It is important to distinguish the target to avoid boomerang effects; universal and binding precommitment systems are effective; a focus on limiting the time spent is priority.	To better design implementation conditions and monitor fidelity.
20. Self-exclusion	Ariyabuddhiphongs, 2013 (10); Drawson, 2017 (14); Gainsbury, 2014 (14); Ladouceur, 2017 (9); Livingstone, 2014 (18); McMahon, 2019 (11); Matheson, 2018 (7); Williams, 2012 (16)	47	A conclusive statement on the effectiveness of self-exclusion cannot yet be offered because of methodological problems, implementation discrepancy and inconsistent results. Self-excluders generally experience benefits from the program.	The reviews analyzed offer several suggestions about the effectiveness of implementation conditions and elements that should be included in self-exclusion programs were suggested.	To better design implementation conditions and monitor fidelity.

N = number of unique studies.