You ' re pretty much correct on all counts . Cast speed is basically a timer that checks if current time max time . SPD and other cooldown reduction CDR effects just decrease or increase the max time . Initially I was going to handle SPD changes by having the cast bar stay at a relative percentage . For example , if you ' re at 1 second out of 5 20 % and a SPD buff expires pushing you to 110 , your current cast time would actually jump up to 210 to preserve the percentage . There ' s several reasons why I didn ' t do that I liked the idea of thresholds where different values of SPD meant different things . For some abilities you ' d need X SPD in order to not waste any , whereas another ability may need Y SPD . At higher levels , SPD buffs are pretty much a constant . You never lose time by having your SPD buff fall off , because of the absurd stacking amounts at that point . Note that this isn ' t a valid excuse for how SPD feels weird in the early game . SPD and CDR , in general has been a sort of pain point throughout the entire development cycle . I honestly didn ' t intend for people to be able to get their casts down to 0 . 1 or 10 per second . I mean looking back at it , it makes a lot of sense that it would eventually get that far but I didn ' t think about it at the time . At this point in time , I probably won ' t change how SPD works in Endless Dream , just because a lot of the game revolves around caststacking and changing it now will only frustrate players who are used to it .