Coin Oracle · Guide
How to cast the coin oracle
Three coins, six throws, one hexagram — and, when a line is old, a second hexagram too. This page is the method end to end: what each coin is worth, why the totals run from six to nine, and what the site does with the six numbers once you have them.
What you actually need
Three coins of the same kind. The metal does not matter, the denomination does not matter, and the coins do not need to be Chinese — what the method uses is simply that each coin can land two ways. Add a pen and a scrap of paper, because six numbers are easier to keep than six numbers are to remember.
If you have no coins to hand, the casting page throws for you with the browser's ordinary random numbers. The reading is identical either way: once the six values exist, the coins have done their whole job. Nothing is sent anywhere, and nothing is stored — the throws happen on your own machine.
Why a coin is worth three or two
Each coin contributes a number rather than a side: heads counts three, tails counts two. Three coins therefore add up to one of exactly four totals — 6, 7, 8 or 9 — and each total draws one line of the hexagram. Nothing else in the method requires the coins after that.
Chinese sources write the same scheme with different words. They count the blank side (背) as three and the inscribed side (字) as two. So if you compare this page with a Chinese text, 背 lines up with heads, not with 字. The arithmetic is identical — three of the three-value side is an old yang line under either name — and this page says heads and tails because a coin in an English-speaking pocket has those.
The four totals
- 6 — three tails. Old yin: a broken line that changes into a solid one.
- 7 — one head, two tails. Young yang: a solid line that stays as it is.
- 8 — two heads, one tail. Young yin: a broken line that stays as it is.
- 9 — three heads. Old yang: a solid line that changes into a broken one.
The distinction that carries the reading is old versus young, not yin versus yang. Six and nine are old: they are at the end of their run and turn into their opposite. Seven and eight are young: they stay exactly as they were drawn. A line that turns is called a changing line, and changing lines are the only thing that can produce a second hexagram.
Six throws, bottom line first
Throw all three coins, note the total, and write it down. That is the first line, and it is the bottom line of the hexagram. Repeat until you have six values; the sixth throw is the top line. This ordering is not a detail — read the same six numbers from the top down and you get a different, entirely plausible hexagram, which is the classic way to reach a confident wrong answer.
The casting page keeps the order visible. The stack grows upward as you throw, newest line on top, so what you see on screen matches the order in which the lines were produced, and each row is labelled with its position from first to top. Once six values are in, the page also names the moving lines the way a Chinese text would: 初九 for a yang line in the first place, 六二 for a yin line in the second, and so on through 上. That vocabulary is worth having even if you never look anything up, because it is how lines are referred to.
How six lines become a hexagram
Six values, each solid or broken, bottom line first. The lower three lines make one trigram, the upper three make another, and the pair of trigrams names one of the sixty-four hexagrams in the King Wen sequence. Sevens and nines are yang and draw solid; sixes and eights are yin and draw broken. That is the entire translation from coins to figure.
Because a hexagram is just a pair of trigrams, the eight trigrams are the whole alphabet: 乾 Heaven, 兑 Lake,离 Fire, 震 Thunder,巽 Wind, 坎 Water,艮 Mountain, 坤 Earth. This site derives the King Wen number from that pair rather than transcribing sixty-four six-bit strings by hand, and a test asserts that the grid covers all sixty-four combinations exactly once — a single transposed digit in a typed table would otherwise produce a wrong hexagram with no error anywhere.
Changing lines and the second hexagram
Take the six values and turn every old line into its opposite: a 6 becomes solid, a 9 becomes broken, and 7s and 8s stay put. The result is another six lines, and therefore another hexagram — the relating hexagram, the one the cast is turning into. The site marks the lines that move on the figure with a circle for old yang and a cross for old yin, so the change is visible without doing any arithmetic.
When nothing moves there is no second hexagram, and the primary one is the whole answer — there is nothing to turn. When several lines move, they all turn at once, and the relating hexagram is read as a whole rather than as a stack of separate changes.
The odds, plainly
Three coins that cannot cheat produce 6 one time in eight and 9 one time in eight; 7 and 8 come up three times in eight each. Per line, that is a one-in-four chance of being old and three-in-four of being young. Six independent lines therefore produce a cast with no changing lines at all about one time in six, so most casts do carry at least one — which is worth knowing before treating every change as a dramatic event. Nothing in the arithmetic makes a changing line rare enough to be an omen in itself.
Reading the cast
This site prints a short essence and a brief counsel for each of the sixty-four hexagrams, plus the same four states used by the other tools — open, steady, held, closed. It does not decode the classical line texts, and it does not quote commentary it cannot show you. That restraint is deliberate: a line text lifted out of its context is one of the easiest ways to be told something confident and useless.
Use the hexagram as a description of the situation you are already in, drawn in a vocabulary you would not have reached for by yourself. It is not a prediction, and it is not advice in any professional sense — nothing here is medical, legal or financial advice.
Keep the six numbers
After the sixth throw the page shows the stack and the reading, and that is all the site keeps: reload and it is gone. There is no account, no stored cast and no cookie holding it. If you want to keep a cast, copy the six totals in order, bottom first — 7, 8, 6, 9, 7, 7 is a complete record, and anyone can rebuild the same hexagrams from it, including the relating one.
Where to go next
Cast a reading — six throws, the figure as it builds, and the changing lines marked. All sixty-four hexagrams are listed in King Wen order with a one-line reading each, which is the fastest way to see where any cast sits. The companion guides cover the site's other traditions: what Xiao Liu Ren is and how to read the almanac.