Korean flashcards should be Hangul-first. Romanization can help a beginner get started, but it should not become the thing the learner studies. The written word is 학교 ("school"), not hakgyo.
That is the Korean rule: Hangul is the card; romanization is support.
Rule 1: Keep Hangul Primary
Korean is written with Hangul syllable blocks. Once a student learns the alphabet, Hangul becomes the fastest path to real reading. A flashcard that puts romanization first slows that down.
The front of the card should show the Korean word: 여자 ("woman"), 먹다 ("to eat"), 한국 ("Korea"). Romanization can appear beneath it when the learner wants help, but it should not replace the script.
Korean Hangul-first flashcard
Rule 2: Let Students Hide Romanization
Romanization is useful at the beginning. It helps a student type searches and connect sounds to Hangul. But once Hangul is familiar, romanization can become visual noise. It gives the eye an easier path and lets the student avoid reading the script.
That is why romanization belongs behind a setting. Beginners can show it. Stronger readers can hide it.
Korean review without romanization
Rule 3: Do Not Borrow European Grammar Rules
Korean does not use articles like el or la. It does not use masculine and feminine noun pairs. It should not inherit plural-display rules from Spanish or French flashcards.
This sounds obvious, but generic flashcard systems often flatten every language into the same template. Korean needs a simpler display contract: show the Hangul word, optionally show romanization, and keep the English definition clean.
How Ludus Applies These Rules
Ludus makes Korean searchable by Hangul and romanization, but display stays Hangul-first. If a learner types yeoja, search can find 여자 ("woman"). The card still shows 여자.
That distinction matters. Search should meet the learner where they are. Review should train the learner toward the language.