FlashBoss: Spaced Repetition and Boss Fights
FlashBoss is a study tool in RPG armor. To learn a language you need surprisingly few things. Trust that your effort won't be wasted, exposure to new language at your level, re-exposure to the material as it begins to fade, and a reason to come back to your desk, where the learning happens.
Speaking is a real-time strategy game; FlashBoss is the same game turn-based. You make the same moves — recall, build, answer — but with time to think.
The shape of the course
Complete language courses cover 3,000 of the most useful words in daily use, with high-quality text-to-speech audio on every card.
Included free: English Advance and English Adept
English Advance — don't get held back. Paperwork English: the forms, letters, appointments, and offices that run a life. Master the language that decides things — or take the full British layer as a brush-up before a season in the UK.
English Adept — become adept in English. For anyone with the quiet ambition to articulate themselves well: 1,000 words chosen for their cultural weight and their precision, to help you think clearly, speak clearly, and understand the world with a little more nuance.
German Core, Esperanto Core and the Toki Pona pack are also included free.
How FlashBoss teaches
Each card sets a target word in example sentences at your current level. Words come in thematic clusters, and every cluster is gated by a boss fight: win it and the cluster graduates — your deck gets smaller as you go. Your choice of master sets how much you study. The cluster bosses decide when you move on.
Free resources online
Free word lists and full lesson lists for every pack are online, with a sample of every voice and a playable boss-fight demo. Link in the right sidebar; the manual link opens the voice samples.
Two ways to play
Work the structured course at your master's pace — or skip the syllabus and just fight. Every tier you clear becomes a low-stakes boss rush, for unlimited review.
Bank days off
Once the day's work is done, you can use a magic spell to bring tomorrow's workload forward — but be careful.
Boss fights
Each cluster ends in a duel: one step forward for a correct answer, two steps back for a mistake. As you practice, your flashcards are ranked by difficulty. The first two spaces deal you your easiest cards, and the last two, the hardest. This means you cannot defeat a cluster without facing your biggest challenges.
Choose your master
Master Cards a day New words 🐺 Luna 8 3 🐉 Shen 13 5 ⚫ Claude 13 5 🦉 Odiin 21 8 🦊 Kitsune 34 13 🦅 Aquila 34 13
Pronounce anything
FlashBoss ships its own neural text-to-speech engine, and it is not locked to the cards. Press Ctrl+P on any screen to open the pronounce window: paste in any text — a letter, a homework sentence, a word that scares you — and hear it spoken properly, or save the audio to keep. Use it as a read-aloud tool for anything you are studying.
Global keys: Ctrl+L — interface language · Ctrl+P — pronounce window · Ctrl+E — Esperanto word analyzer · A — audio on/off during review.
The packs
Five starter packs ship free:
English Advance — the practical English of adult life: forms, letters, the fine print. 500 words.
English Adept — sharper English for how you think, write, and speak. 1,000 words.
German Core — the first 1,000 words of German, including a cultural integration section.
Esperanto Core — one of the easiest languages to learn; 1,000 words goes far.
Toki Pona — the complete course in the world's smallest language. Learn it in a week; think in it for life.
Further FlashBoss content:
English Core — English as a foreign language for German, Japanese, Spanish, Chinese and Russian speakers: the first 1,000 words, fully playable in your language, with Pareto packs continuing to 3,000.
Latin Roots — build English vocabulary by recognizing the parts that make the whole. 1,000 words over 500 cards.
German Roots — the Germanic backbone of everyday English. 1,000 words.
Norman Roots — the French that arrived in 1066 and stayed. 1,000 words.
Greek Roots — the vocabulary of science, medicine and philosophy. 1,000 words.
Full 3,000-word courses in German, Spanish, French, Italian and Esperanto — beginner to advanced.
New releases every Thursday.
English text is American by default. The Voices: English (F) pack speaks British English and switches every English text field to British spelling by itself; prefer British text without the voice, and it's one setting away: Help & Options → Preferences → Language preferences → English spelling.
Developer Note
FlashBoss is a sanctuary for learning as much as it is a game. Most of the pleasure to be taken comes from learning the satisfaction of pattern recognition at your own pace.
FlashBoss is also a 'question' generator. When something specific puzzles you — why this case, why that word order, why the ending changed — this question will allow almost any AI to give you the exact answer you need, at a level you can understand, for 'to ask the right question is already half the solution.' — Carl Jung.
— Master Odiin (August 28th 2026)
