Shatterheart is a d20 roll over system, but with heavy game mechanical changes to the classic ‘d20’ mechanics designed to speed play and enable players to make clear hard choices on use of their resources. It uses only four attributes BEEF, JOCK, GEEK and RIZZ. Almost all rolls involving player agency are Skill checks, including class specific skills, weapons skills and spell casting skills. These are called TS rolls, to succeed, to strike, to spell cast. An innovative system call poker initiative is used; however, initiative will need to be rolled infrequently (as it is always on) so that there will be no delay to play at the start of combat. Melee attacks which are defended by a weapon welding enemy are resolved by a modified blackjack dice system. ‘Dead Turns’ don’t exist; you always have choices in a turn to set up more powerful attacks and even if you don’t hit in a turn, you can positionally shape the battlefield. An escalation dice is used to build encounters to a climax. There is only one roll (hence one role) of the dice for everything on a players turn. There are no multiple player attacks. Innovative mechanics are used to replace the multiple dice rolls & attacks used in other systems. In place of multiple attacks, the system uses a degree of success system which can dramatically upscale critical damage, or gain tactical advantages on future turns, even on a miss. Monster do and take much more damage than players so only good tactics designed to maximise damage can tip the odds. This is designed to drastically speed play. We recommend use of blitz chess app to ensure most small combats take no more than half an hour and climatic combats no more than 45 minutes. The game uses a three-action economy – however in line with the one roll principle only one attack, spell cast causing damage, move or heal per turn. Players can make actions either before and/or after a dice role to use their abilities to achieve dramatic effects. For monsters a simplified asymmetric two action economy system is used amongst many other asymmetric elements to make the GMs life easier. The game unusually has a full 20 levels from day one. All maths have been rescaled using a rigorous bounded accuracy approach, so that all level play is viable. The system avoids hit point (squish point) bloat, uses a simplified hearts system to track damage. All higher-level characters are still vulnerable to a stab or a poison. The games take classes seriously with a clear objective of making all ‘classic’ classes more fun to play and well balanced. Characters are highly customisable as they level avoiding the need altogether for game breaking (and often ridiculous) sub classes. The emphasis is on all character abilities and advancements having a clear rationale in the game world. It uses diegetic progression and no XP. Progression is bought and achieved through spending on training, gifts to religions and charity, travel, learning and carousing. This gives an incentive to avoid combat and to explore. Player abilities use a focus point system including spell casting (mana). Finally encounters design is made much easier by adjusting the stats of monsters and their typical numbers to fit a ‘skull rating’ for a party – not vice versa. The game allows for three styles of play, from abstracted combat distances to detailed grid based tactics, to new fangled resolutions.