Saju Terms, Explained in Plain English

Saju takes the year, month, day, and hour of your birth and converts each into two characters (a Heavenly Stem plus an Earthly Branch) — eight characters in all. Reading which of the Five Elements (Wood, Fire, Earth, Metal, Water) those eight characters carry, and how they attract and collide with one another, is how a Saju reading describes your temperament and the flow of your life. The key reference point is the Heavenly Stem of your birth day (the Day Master) = "you" — and working out what every other character means to "you" is the backbone of Saju interpretation. Knowing the terms below will make your Saju Chart · Free results far easier to read.

1. Saju Palja · Myeongsik · Wonguk

• Saju (四柱) = the four pillars: the year, month, day, and hour pillars.
• Palja (八字) = the eight characters. Each pillar has one character on top (a Heavenly Stem) and one below (an Earthly Branch) = 4 × 2 = 8.
• Myeongsik (命式) / Wonguk (原局) = those eight characters laid out as a table — your natal Saju chart. "Casting my Saju" simply means drawing up this chart.

Put simply: you enter your birth date and time → after calendar and solar-term calculations, out comes an eight-character table (solar terms are the 24 seasonal turning points of the traditional calendar — more on them in section 11), and that table is your chart.

If you don't know your birth time, a reading can still be done with the six characters minus the hour pillar (with somewhat lower precision).

2. The 10 Heavenly Stems · The 12 Earthly Branches

The characters in a chart come from a fixed set of symbols.

• 10 Heavenly Stems (天干): 甲 (Gap) · 乙 (Eul) · 丙 (Byeong) · 丁 (Jeong) · 戊 (Mu) · 己 (Gi) · 庚 (Gyeong) · 辛 (Sin) · 壬 (Im) · 癸 (Gye).
• 12 Earthly Branches (地支): 子 (Ja) · 丑 (Chuk) · 寅 (In) · 卯 (Myo) · 辰 (Jin) · 巳 (Sa) · 午 (O) · 未 (Mi) · 申 (Sin) · 酉 (Yu) · 戌 (Sul) · 亥 (Hae).

The Earthly Branches are the 12 zodiac animals. 子 = Rat, 丑 = Ox, 寅 = Tiger … 亥 = Pig. So "your animal sign" simply means the branch of your birth year.

Pairing the stems with the branches produces the 60 gapja (甲子, 乙丑 … 癸亥), a cycle that comes full circle every 60 turns. That is why hwangap (回甲) — the traditional Korean celebration of one's 60th birthday — marks exactly 60 years.

3. The Five Elements (五行) and Yin–Yang (陰陽) — Saju's Basic Ingredients

Every stem and branch belongs to one of five energies (the Five Elements).

The elements either help one another (the generating cycle, 相生) or suppress one another (the controlling cycle, 相剋).

• Generating (help): Wood → Fire → Earth → Metal → Water → Wood (Water feeds the tree, the tree feeds the fire…).
• Controlling (restraint): Wood controls Earth, Earth controls Water, Water controls Fire, Fire controls Metal, Metal controls Wood.

The main thread of a Saju reading is to look at "which elements are abundant (in excess) and which are missing (deficient) among my eight characters," then top up what is lacking and rein in what overflows to restore balance.

Yin–Yang is each character's (+)/(−) polarity. Even within the same element the grain differs — 甲 is yang Wood (a great tree), 乙 is yin Wood (a flowering plant). Yin–Yang is what decides "same polarity or different?" in Ten Gods and compatibility calculations.

4. The Day Master (日干) — "You" in the Chart

The Heavenly Stem of your birth day is called the Day Master (日干, ilgan), and it stands for "you" yourself. Every Saju interpretation unfolds as "seen from the Day Master (me), what is each of the other characters?"

• Someone whose Day Master is 甲 (yang Wood) = a temperament like a great tree at their foundation.
• The Day Branch (日支, the branch of your birth day) = the spouse palace. It is read as the seat of your home and partner, so it carries the most weight in compatibility.

5. The Ten Gods (十神) — 10 Ways the Other Characters Relate to "You"

Taking the Day Master (you) as the reference point, each of the other characters is given one of 10 names based on how it relates to you through the elements (does it help you, control you, or get controlled by you?) plus whether its Yin–Yang matches yours. Once you know a character's Ten God, you can read whether it stands for money, work, people, or honor in your life.

"Direct (正)" means the polarities differ, so the bond forms gently → stability, orthodoxy. "Indirect (偏)" means the polarities match, so the effect hits hard → tilt and volatility. One axis of compatibility: for a man, the Wealth stars (Direct/Indirect Wealth) = spouse; for a woman, the Officer stars (Direct Officer/Seven Killings) = spouse.

6. The Twelve Life Stages (十二運星) — an Energy's "Seasons of Life"

These are 12 labels for the stage of energy the Day Master takes on when it meets each branch, likened to a human lifetime (being born, growing, aging, fading away).

長生 (birth) · 沐浴 (bathing — immaturity) · 冠帶 (coming of age) · 建祿 (standing on one's own) · 帝旺 (peak) · 衰 (decline) · 病 (illness) · 死 (ending) · 墓 (storage) · 絕 (severance) · 胎 (conception) · 養 (nurture).

Put simply, it is a "seasonal marker" telling you whether your energy at that position is just rising, at its height, or winding down.

7. Sinsal (神煞) — Special Markers Made by Particular Combinations

Sinsal are nickname-like markers attached when particular branches or combinations meet. Some are auspicious (吉), some inauspicious (凶), and they turn up especially often in romance and compatibility content.

Sinsal are supporting indicators. They never determine fate on their own — they are read as reference points within the overall balance.

8. Yongsin (用神) — the Element Your Chart Needs Most

The element most needed to bring the eight characters into balance is called the Yongsin — the "useful element." If the chart runs hot, you pick a cooling energy; if it runs cold, a warming one; if one side overflows, something to rein it in.

• Each school selects the Yongsin differently (eokbu strength-balancing, johu climate, byeongyak remedy, tonggwan mediation, jeonwang follow-the-dominant), so there is no single right answer. Byeolja's free Saju tool adopts a climate-first (johu) rule and shows the candidates and the reasoning together, avoiding a single verdict.
• In practice: colors, directions, and career fields matching your Yongsin are suggested as "supportive energies." In compatibility, a partner who supplies the Yongsin energy you lack earns bonus points.

9. Daeun (大運) and Annual Luck (歲運) — the Flow of Time

If the natal chart (the eight characters you were born with) is a "fixed map," then luck (運, un) is the "time" that passes over it.

• Daeun (大運): the big current that shifts roughly every 10 years — the 10-year luck pillar. Its starting age and direction (forward or reverse) are set by the Yin–Yang of your birth year × your sex, plus the distance from your birth date to the next solar term (or the previous one, when the luck runs in reverse).
• Annual luck (歲運, seun): the luck of that single year (e.g., 2026, the Byeong-O 丙午 year). It changes every year.
• Monthly luck (月運): the luck of the month.

Today's Fortune is built by computing how today's stem-branch (the daily iljin), the annual luck, and the monthly luck relate to your Day Master through the Ten Gods and Five Elements (fully deterministic, no LLM — the same person on the same day always gets the same result).

10. Combination · Clash · Punishment · Destruction · Harm · Resentment — the "Chemistry" Between Characters

When Earthly Branches (the 12 characters) meet, they either attract (combinations) or collide (clashes, punishments, and so on). This is the core of reading compatibility and the fortune of a period.

The Heavenly Stems combine too — the Stem Combinations (甲己 Gap-Gi, 乙庚 Eul-Gyeong, 丙辛 Byeong-Sin, 丁壬 Jeong-Im, 戊癸 Mu-Gye) — and when two people's Day Masters form a stem combination, it reads as a strong attraction.

A single pair of branches can trigger clash, punishment, destruction, and harm all at once, so the calculation counts only the strongest one per pair, or caps the deductions, to keep the score from spiraling.

11. Corrections That Make the Calculation Accurate

Even with the same birth date and time, a careless calculation produces the wrong chart. An accurate manseryeok (萬歲曆, the perpetual Saju calendar) has to correct every spot where errors creep in.

• Year and month boundaries follow the solar terms — not January 1st or Lunar New Year. A year begins at Ipchun (立春, "Start of Spring"), and each month begins at the exact entry moment of one of the 12 month-opening solar terms.
• True solar time: Korean standard time is pegged to longitude 135°E, but Seoul sits near 127°E, so actual solar time runs about 32 minutes behind. That can shift an hour boundary and change the hour pillar.
• Daylight saving time: people born in 1948–51, 1955–60, and 1987–88 had their clocks set forward one hour, so 1 hour is subtracted.
• Standard-time history: the reference longitude for Korean standard time changed across eras (127.5° vs. 135°), and each historical window is applied.
• Lunar ↔ solar conversion: leap months and long (30-day)/short (29-day) lunar months are handled precisely (aligned with the Korea Astronomy and Space Science Institute, KASI).
• The Ja-hour (子時) boundary: whether 11 pm–1 am opens the new day (the yajasi "late Ja hour" convention) or the day flips at midnight (jeongjasi) is kept as a separate, explicit policy.

12. The 144 Gua of Tojeong Bigyeol — How the Year-Ahead Reading Works

Tojeong Bigyeol is the year-ahead fortune Koreans have consulted at the start of the year since the late Joseon dynasty. It uses its own system of 144 gua (卦) — not the 64 hexagrams of the I Ching.

• A gua is a three-digit number: upper gua (1–8) · middle gua (1–6) · lower gua (1–3) → 8 × 6 × 3 = 144 gua.
• The casting formula (the traditional Korean method, based on the lunar calendar and Korean counting age — the age system in which a newborn is 1 and everyone gains a year at New Year):
  • Upper gua = (counting age + Taese number) ÷ 8, take the remainder
  • Middle gua = (days in your lunar birth month + Wolgeon number) ÷ 6, take the remainder
  • Lower gua = (lunar birthday + Iljin number) ÷ 3, take the remainder
  • (The Taese, Wolgeon, and Iljin numbers are fixed values looked up in traditional reference tables.)
• Each gua carries an eight-character classical Chinese verse (e.g., "東風解凍 枯木逢春" — "the east wind melts the ice, and the withered tree meets spring") plus a summary for the year and month-by-month readings.

The classical Chinese verses of the 144 gua (the year summaries) are in the public domain, but the modern commentary is our own original work. The free Tojeong Bigyeol page shows your gua number, a one-line gist, and one-line monthly readings; Bokja's full commentary and the premium report open with coins.

13. The 16 Types as Read from Saju (Saju × Personality Type)

In step with today's culture of dating and self-discovery, we map Saju's Five Elements and Ten Gods onto the four personality-type axes (extraversion/introversion, sensing/intuition, thinking/feeling, judging/perceiving) to present "the 16 types as read from Saju."

• Only one axis has solid backing: strong Wood/Fire leans extraverted (E); strong Metal/Water leans introverted (I) (supported by academic research). The other axes rest on conventional readings, so they are used only as tendencies (continuous scores), never as a fixed 1:1 mapping.
• In practice: even without taking a personality test, you see a Saju-based estimated type; if you do have real test results, we compare your innate leaning (Saju) with the self you've built (the test) as self-discovery content.
• A note on naming: MBTI is a registered trademark, so we say "the 16 personality types."

This mapping in Saju 16 Types is for fun and self-reflection — it is not a scientific verdict.

14. Saju Compatibility — the Two-Stage Gate

Two people's compatibility is computed in two layers: Saju (your innate grain, what you were born with) + personality type (the self you've built since). The philosophy: "When the Saju doesn't align, personality type can compensate — but a critical flaw can't be papered over completely."

1. Stage 1 — the Saju compatibility score (0–100): starting from a base of 50,
   • A Day Master stem combination (strong attraction) +, a Day Branch six-combination (the spouse combination) +, a three-harmony +
   • Clash/punishment/destruction/harm/resentment −, including the Day Branch clash (a critical marker)
   • Spouse-star points + for the man's Wealth stars and the woman's Officer stars
   • + when your partner supplies the Yongsin energy your chart lacks
2. Stage 2 — adjustment by personality type: personality compatibility makes the biggest difference when the Saju score sits in the middle band (40–79). But a critical flaw like a Day Branch clash imposes a ceiling (e.g., 59 points) so the acquired layer can never cover everything.
3. Explainability: the itemized contributions are shown exactly as computed — "Day Master stem combination +20 · Day Branch six-combination +15 · Day Branch clash −20 · Yongsin complement +8 · shared intuition +12."

A Saju Compatibility score does not predict whether a relationship will succeed or fail. It is for fun and self-reflection, and it never issues verdicts like "breakup certain," "destiny," "100%," or "marriage guaranteed." The framing is "a tool that helps you understand your differences and get along better."

Appendix. Terms Worth Reviewing with Each Tool