The gaming industry is a multi-billion dollar business has evolved from video arcade games in the 1970s/80s to video game consoles and online games in the 1990s/2000s. Today, games can be played on smart phones and tablets which are initially offered for free. They make money later by offering in-app upgrades which promises to enhance the gaming experience. When a gamer engages in this purchase, the term used is in-app purchasing. Normally, a frequent gamer is interested to buy upgrades. For this, a game company must understand the needs and wants of a gamer, and design an intelligent game system which gathers and process information about the behaviour of a gamer when he/she interacts (plays) with it. The game system will suggest a list of in-app(s) which are priced according to the effectiveness for the gamer to upgrade. This research-in-progress paper presents a theoretical framework to study in-app purchasing. The In-App Purchasing Theoretical Framework is backed by Behavioural Game Theory, which is to examine gamer’s behaviour, and Theory of Consumption Values, which identify the game’s values which are gained from his/her gaming experience.