According to the latest Emission Gap Report 2020 of the UN Environment Programme, the Parties to the Paris Agreement would have to triple their emission reduction ambitions to reach the agreed 2 °C target, and even quintuple them to approach the 1.5 °C limit. The success of the international climate change regime will therefore be measured by its ability to deliver these substantial increases in ambition in a timely manner. The Paris Agreement responds to this challenge with a complex and innovative regulatory arrangement, the interplay of which can be described as an 'spirale of ambition'. With its specific combination of procedural obligations, institutional arrangements and substantive principles, it forms the core structure of the post-Paris international climate change regime. However, it was not until the adoption of the so-called 'Rulebook' to the Paris Agreement at COP24 in Katowice 2018 that the individual elements of the 'spiral of ambition' were given their applicable form. The article examines the operationalisation of the central elements of the ambition spiral through the Katowice decisions and evaluates them with regard to their functional interplay. Beyond the individual elements examined, three strategies of the Parties can be identified, which additionally sharpen the procedural and material incentive structure of the 'spiral of ambition' for a joint increase in ambition and which might be further optimised in the future: First, the curbing of national discretion and built-in flexibility by further specifying the accountability obligations and establishing additional justificatory requirements. Secondly, the further strengthening of transparency and the inclusion of »non-party stakeholders«. Thirdly, the strengthening of procedural elements which promote learning processes at the planing and implementation stage at the national level as well as shaping the international climate protection regime itself as a law capable of learning.