Motivation researchers (REF) have reliably demonstrated the ability to enhance a variety of affective, behavioural, and cognitive outcomes by modifying the practice environment to focus on process (i.e., mastery) rather than outcome goals. Whilst effective in practice, adapting the competitive environment within sport has proven more problematic. Rather than promoting an autonomy supportive climate that may positively enhance the athletes’ intrinsic motivation, for many, the competitive environment stifles development (REF). In an effort to tackle this issue, Burton, Gillham & Hammermeister (2011) proposed a conceptual framework for what has now come to be known as ‘Competitive Engineering (CE)’. CE is defined as modifying the structure, rules, facilities, and/or equipment used within sporting competition in order to have a positive effect on affective, behavioural and/or cognitive outcomes. The current proposal aims to engineer the competitive environment in association football and proposes the introduction of what have coined The Six Goal Lead Rule (SGLR). The SGLR aims to safeguard against the psychological harm caused by frequent heavy losses that may influence retention rates in association football. Despite the obvious benefits of introducing this safeguard, there are a number of issues to be worked through when implementing such a rule change that this PhD could support. For example, when to implement the rule (e.g., is there an optimal window where it is effective to stop the game), how to restructure the competitive environment (e.g., power play or reorganising teams), who implements the aforementioned (e.g., the referee, coaches, players), and most importantly, what effect does this have on the players’ enjoyment (i.e., affective), levels of physical activity (i.e., behaviour), and psychological well-being and intentions to continue playing (i.e., cognitive).