Reflex Duel is a free online reflex game where you face a computer rival across a dark courtyard, each of you beside a drum, with a paper lantern hanging between you. After a wait you cannot predict, the lantern lights — and whoever strikes first takes the point. Strike before it lights and it is a false start: the point goes to the other side. The rival plays by the same rules, so it can jump the gun too. Climb a ladder of twelve rivals from slow Old Moss the tortoise to Master Crane, with amber flickers, red crosses and passing birds to bait you, and sun-or-moon signals where only the matching drum counts. No download, no sign-up, and it plays with a tap, a click or a key.
How to play Reflex Duel
- Press Start or tap the scene. Each point begins with the lantern dark — rest your finger on the key or the screen and watch it.
- The moment the lantern lights white with GO!, strike your drum: tap the scene, or press Space, Enter or an arrow key. Your reaction time is counted from the moment the light appears.
- Strike first and the point is yours; if your rival strikes first, it is theirs. Striking before the lantern lights — or less than 100 ms after it, too fast to be a reaction — is a false start and gives the point away.
- From stage 3 the lantern can flicker amber, from stage 5 it can glow red with a cross, and from stage 10 a bird can fly past it. None of these is the signal: hold still and wait for the real light.
- From stage 7 the lantern shows a sun or a moon. Moon means your left drum (←, F, or tap the left half), sun your right drum (→, J, or tap the right half). The wrong drum gives the point away — for your rival too.
- First to five points wins the match and unlocks the next rival. Any win earns a star; concede fewer points for two or three stars.
Tips
- Watch the lantern, not the clock. The wait is drawn at random every point, so counting in your head only leads to false starts.
- Keep your finger resting on the key or the screen. Moving your hand into place costs more time than the reaction itself.
- A false start costs a whole point, the same as being slow. Against a slow rival like Old Moss, a calm strike at 350 ms usually wins.
- On sun-or-moon stages, decide which drum before you swing. Reading the symbol takes a moment, but the wrong drum is a lost point however fast it was.
- Twitchy Nutmeg the squirrel jumps the gun now and then. Stay still and those points come to you for free.
FAQ
Is Reflex Duel free to play?
Yes. Reflex Duel is completely free to play online with no download, no account and no in-game purchases.
How does a point work?
The lantern stays dark for a random wait, then lights. Whoever strikes their drum first after that takes the point. Your time and your rival’s are shown after every point, both counted from the moment the light appeared. First to five points wins the match.
What counts as a false start?
Any strike before the lantern lights, including at an amber flicker, a red cross or a passing bird. A strike less than 100 milliseconds after the light also counts — that is too fast to be a reaction, the same line sprint starts use. A false start gives the point to the other side, and the rival can make one too.
How fast are the rivals?
Old Moss the tortoise reacts in about 470 milliseconds on a typical point, and each rival up the ladder is quicker, down to Master Crane at under 300. Every rival has its own spread, so even a fast one is sometimes slow, and the later rivals rarely fall for bait. Most people react to a light in somewhere around 200 to 300 milliseconds.
What are the sun and moon signals?
From stage 7 the lantern lights with a sun or a moon instead of GO!. Moon means strike your left drum, sun your right. The wrong drum gives the point away, so the challenge is reading the symbol quickly as well as reacting.
Can I win by guessing when the light will come?
Rarely. We tested a player who strikes at the same moment every point, at every beat from 0.3 to 6.5 seconds in steps of 0.2: on every stage it won fewer than one match in five over 41 matches, because most guesses land before the light and the rest are too late or under 100 ms.
How are the stars and the rivals set?
By measurement. Simulated players with realistic reaction times, false starts and slips at bait played every stage: each rival was tuned so players win less often stage by stage, and the two- and three-star lines are the points a regular and a sharp player concede in their middle win over 41 matches (three stars always asks for fewer than two). Any win is one star.
Does my screen or frame rate matter?
No. Reactions are counted from the frame that showed the light, for you and your rival alike, so the same reaction gives the same result at 60 Hz or 144 Hz. The signal is the light alone — sounds only play after a point is decided — and switching tabs pauses the duel and replays the point instead of losing it.
Does Reflex Duel work on a phone?
Yes. Tap anywhere on the scene to strike, or the left or right half on sun-or-moon stages. It plays upright or sideways, and with a keyboard on a computer.
How is Reflex Duel different from the Reaction Time Test?
The Reaction Time Test measures your average against a target on your own. Reflex Duel puts a rival on the other side of every point, with bait to resist and sun-or-moon choices to read, so you win points by being quicker than someone rather than by hitting a number.