I run a casino in the immortal realm.

Qingyunfang Market.

The signboard of "Plum Spirit Wine" glowed with a magical light in the twilight. This tavern was located on a street corner and had many disciples coming and going, but business was so-so in the evening, and the private rooms on the third floor were almost empty.

Zheng Yifei had booked a window seat on the third floor in advance, and ordered a pot of premium plum spirit wine, two plates of braised spirit beast meat, and a plate of salt-baked spirit peanuts.

Xu Jian arrived right on time.

The man hadn't changed much since the last time we met; he was still as slovenly as ever—his hair was askew, his robe was stained with iron filings and cinnabar, and he had seven or eight storage bags of varying sizes hanging from his waist, which jingled as he walked.

The only difference is that her complexion has improved a lot.

"Chief Inspector Zheng, what's the work this time?"

Xu Jian plopped down, poured himself a bowl of wine, downed it in one gulp, wiped his mouth, and said, "Not enough gambling equipment? Want to add more?"

"It's not an additional order."

Zheng Yifei poured him more wine and pushed the plate of braised meat over to him.

"Brother Xu, I'd like to do a business deal with you."

Xu Jian picked up a piece of braised meat, stuffed it into his mouth, chewed it a couple of times, and rolled his eyes.

"What kind of business?"

"Open a gambling equipment workshop."

Xu Jian paused for a moment while chewing, then continued chewing, swallowed, and picked up another piece.

"Gambling equipment workshop? Your Tianyuan Casino doesn't have enough gambling equipment?"

"It's not for Tengen."

Zheng Yifei picked up the wine bowl, but didn't drink it. He twirled it in his hand and said, "It's a new gambling device, something no one has ever seen before. After it's produced, it's deployed to various gambling dens and markets. Every single one of these devices is constantly earning spirit stones."

Xu Jian's hand froze in mid-air, the braised meat hanging on the tip of his chopsticks, oil dripping onto the table.

"Keep making money?"

"Yes, no dealer is needed, no one needs to watch over it. It's just placed there, and the gamblers insert their own spirit coins to play. The gambling device automatically spits out spirit coins, but it spits out fewer than what's inserted."

Xu Jian put the braised pork down.

He was a third-tier weapon refiner, and he understood the principles of mechanical puppets better than anyone else. His technology for using spirit stones to drive combat puppets was very advanced.

But what if this system were used on gambling equipment?

"What are you talking about?"

Xu Jian's tone changed; his casual, conversational manner at the dinner table vanished, replaced by the seriousness he displayed when discussing technical matters related to equipment repair.

Zheng Yifei took out a piece of spiritual paper from his storage bag and unfolded it on the table.

The paper shows a sketch of a rectangular cabinet with three circular rotating wheels side by side on the front, a coin slot at the top, a coin dispenser at the bottom, and a lever on the side.

"I call this thing a 'transfer machine'."

Xu Jian leaned closer to look, his brows furrowing.

"The gambler inserts a spirit coin into the coin slot, pulls the lever, and the three reels spin simultaneously. After they stop, if the patterns on the three reels match, the reward is dispensed from the coin dispenser—the reward ranges from two to one hundred spirit coins depending on the pattern."

Zheng Yifei pointed to the grid on the reel with his chopsticks.

"Each reel has twenty slots, and I decide the patterns. The number of patterns determines the probability of winning. But no matter how it's designed, in the long run, gamblers will always put in more spirit coins than they'll get out."

Xu Jian stared at the picture for more than ten breaths, his mind already racing.

"You mean... this roulette wheel, like the roulette wheel in your casino, has a fixed house advantage?"

"More ruthless than roulette."

Zheng Yifei put down his chopsticks: "Roulette requires a dealer, a gambling table, and a venue, but the roulette machine doesn't. Just put a machine in front of a shop and it makes money from morning till night."

I've done the math—a single transfer machine can conservatively generate at least fifty spirit coins a day, and with the dealer's profit margin set between 15% and 20%, that means each machine can net seven to ten spirit coins per day.

Xu Jian's eyelid twitched.

Seven to ten spirit coins doesn't sound like much.

But what about a hundred units?

What about 1,000 or 10,000 units?

"One thousand machines can generate a net profit of ten thousand spirit coins per day, which is equivalent to one hundred spirit stones."

Zheng Yifei calculated for him: "Three thousand yuan a month. And this is just a conservative estimate. For example, in Sujiafang City, with a population of 300,000, if 500 units are deployed, the daily profit would be—"

"Wait a moment."

Xu Jian raised his hand to interrupt him and took a deep breath.

He had been a weapon cultivator for twenty years and had seen all kinds of magical artifacts and treasures.

Flying swords have high profit margins but long crafting cycles; talismans have low profit margins but high demand.

Qifeng's most profitable product is the Spirit Gathering Array Plate, which sells for 3,000 spirit stones per set. The cost of materials and labor is 1,200, leaving a net profit of 1,800. However, the maximum production per month is 30 sets.

Most importantly, these magical artifacts and treasures are all sold on a one-off basis.

As for the transfer machine that Zheng Yifei mentioned, he had a rough idea of ​​the material cost—a spirit wood shell, a copper rotating wheel, a simple spirit power driving array, and a coin insertion and dispensing mechanism—at most, one machine would cost ten spirit stones.

If you create something with ten spirit stones, you can earn seven to ten spirit coins every day. You'll break even in a month, and after that, it's all pure profit.

Moreover, it requires no human resources.

Xu Jian picked up the wine bowl, took a swig, put it down, and took another swig.

How is profit sharing calculated?

"It's 30% to me, 70% to you, because the operating costs are higher. The transfer machine needs spirit stones to operate, and when it's deployed to a shop, we have to pay rent or commission to the merchants. Maintenance requires personnel, so the profit I actually get is probably less than 30%."

Xu Jian didn't hesitate: "Okay."

Then he fell silent for three breaths, his excitement fading and replaced by a layer of worry.

"There's a problem."

"explain."

"I am a steward of the Weapon Peak, with a cultivation level of mid-Foundation Establishment. I don't have much say in the Weapon Peak. If this kind of thing is launched and the profits are so large, it will attract attention."

"Not to mention outsiders, any of the Foundation Establishment Peak senior brothers within the Light Weapon Peak could easily get me to hand over the blueprints with just a word."

Zheng Yifei nodded. This was precisely the point he wanted to make.

"So I don't plan to expand right away. The first batch will only be fifty units, all of which will be deployed in Sujiafang City. My people will be responsible for their operation and maintenance. Once it's running smoothly, we'll consider expansion."

Xu Jian thought for a moment: "Fifty units is quite a lot, what if the news leaks out—"

"Therefore, I need you to make a vow to Heaven."

Xu Jian's expression froze for a moment.

A vow made in accordance with the will of Heaven is not something to be taken lightly.

Once a cultivator makes a vow to the Heavenly Dao, violating it will result in a backlash from the Heavenly Dao. At best, their cultivation will regress; at worst, their Dao foundation will collapse, which is worse than having their cultivation destroyed by someone else.

"What are the contents of the oath?"

"Two points. First, the core technology of the transfer machine must not be disclosed to outsiders, including blueprints, array structure, and probability design; it cannot be told to anyone."

Second, the transfer machines can only be produced in our workshop; finished or semi-finished products may not be sold to third parties, and we may not authorize others to imitate them.

Xu Jian stared at Zheng Yifei for five breaths.

These two oaths effectively bound him to his fate—he could only cooperate with Zheng Yifei, he couldn't break away from Zheng Yifei to work independently, and he couldn't sell the technology to others.

But on the other hand, taking a 30% cut, for a late-stage Foundation Establishment cultivator like him to have access to this level of business opportunity is like a gift from heaven.

"I, Xu Jian, swear by the Heavenly Dao—"

He stood up, facing the night sky outside the window, his tone calm and steady.

"The core technology of the transfer machine and related gambling equipment shall never be disclosed to any third party for the rest of my life; the production and sale of the transfer machine shall be limited to workshops that cooperate with Zheng Yifei, and shall not be sold or authorized for imitation without authorization. Violation of this oath will be punished by Heaven, and the foundation of my righteous path will be destroyed."

The moment the words fell, an invisible ripple swept across the night sky, so faint as to be almost imperceptible, but both of them felt it.

Heaven has recorded this.

Xu Jian sat back down, picked up his wine bowl, and downed it in one gulp.

"make a deal."

Zheng Yifei took out a stack of spirit tickets and a more detailed blueprint from his storage bag and pushed them in front of Xu Jian.

"Ten thousand spirit stones. Use them to rent a site, build a workshop, and purchase materials. The blueprints indicate the specifications and precision requirements of each component, as well as the number of slots on the spool, the pattern distribution, and the formula for calculating the coin output probability."

"You're the expert in formations, so I can't design them, but you just need to understand the principles."

This world is not powered by electricity, but it has spirit stones as energy. With the help of array formations, it can power magical artifacts, as well as mirror artifacts that can display images. Making a slot machine is not difficult.

Xu Jian unfolded the blueprints, his gaze fixed on the first page.

The anti-counterfeiting mechanism of the coin slot, the random stopping array of the coin reel, and the counting device of the coin dispenser—each component is marked with detailed parameters and principle explanations.

Although the rough sketch of the formation drawn by a cultivator at the ninth level of Qi Refining was crude, the core concept was so clear that it was astonishing.

"This random stop formation..."

Xu Jian pointed his finger at the blueprint. "You used the decay curve of spiritual energy pulses to control the deceleration of the wheel?"

"Yes, the spiritual energy input each time the lever is pulled is slightly different, so the decay curve is different, and the position where the wheel stops is different, so the gambler cannot predict the result."

Xu Jian's breathing became heavier.

The most ingenious part of this design is not the mechanism itself, but that it makes "randomness" a true randomness at the physical level. It is not simulated by the array, but by the uncertainty of spiritual power itself.

No cultivator, not even one at the Golden Core stage, can precisely control the amount of spiritual energy injected each time the lever is pulled.

This means that no one can cheat.

"How long can you produce the first prototype?"

Zheng Yifei asked.

Xu Jian rolled up the blueprints, stuffed them into his storage bag, and stood up.

Give me three days.