RemNote schedules flashcards for practice using one of several spaced-repetition algorithms. The default settings are suitable for most users studying most kinds of flashcards, but experienced users may find it helpful to adjust the algorithm used for all cards or certain groups of cards, as well as the parameters of these algorithms.
We do not recommend configuring custom schedulers until you are familiar with how RemNote works and have been studying flashcards for several months, and you should under no circumstances change settings you do not fully understand. It's easy to make your performance worse rather than better by configuring custom schedulers!
Configuring and assigning schedulers
Each set of scheduling settings (chosen algorithm and parameters) that you define is called a scheduler. One special scheduler is called the Global Default Scheduler and will be applied to every flashcard that doesn't have a different scheduler assigned. In addition, you can create other schedulers which are assigned to specific documents or folders. When deciding which scheduler to use for a particular flashcard, RemNote will check the Rem the card is generated from for a custom scheduler, then its parent, then its parent, and so on until it finds a scheduler, or until it reaches a top-level Rem that has no scheduler (in which case the Global Default Scheduler will be used).
Schedulers can be created and configured in Settings > Custom Schedulers. To assign a document and its children to a particular custom scheduler, choose Customize Spaced Repetition from the Document Menu (... button in the upper-right corner of a document). You can also edit the settings of the selected scheduler from here.
RemNote ships with two scheduling algorithms:
Default: A simple algorithm proprietary to RemNote. Cards go through a series of fixed, exponentially increasing steps. This scheduler can't be customized.
Anki SM-2: An algorithm based on Anki's default algorithm, which in turn is based on an early version of SuperMemo's default algorithm. Cards have an interval (time between the last two reviews) and an ease (representing how hard you've found the card in the past), and the next study time is calculated based on these values. Anki SM‑2 has many parameters and is highly customizable; the settings screen includes an explanation of what each parameter does. You can also read a detailed explanation of how this algorithm works in this article.
Plugins that add additional scheduling algorithms are available, or you can write your own.