Two days later, in the camp of the Han army in the north of the city, at dinner one day, Li Su was called by Liu Bei to eat together.

Eating at the same table is a common courtesy in Liu Bei's camp.

To the extent that Guan Yu and Zhang Fei still have to sleep in the same bed. It's just that Li Su couldn't fall asleep listening to the snoring, so he repeatedly refused.

Walking into Liu Bei's tent, Li Su saw that there were several clay pots and clay pots on the middle of the plan, which were respectively placed with stewed horse legs, boiled horse shoulders, roasted horse steaks, and dead dough cakes.

There's no way, who let the big battle ten days ago get too many seriously injured lame horses and dead horses, and they haven't eaten it until now.

Now in the year of great famine, the hungry people in Tuntian are gathering more and more, and Liu Bei himself has to save military rations, so he ordered all generals and civil servants not to slaughter livestock for meat before the horse meat is eaten.

Although the ancients did not have good preservation methods, the spring in the Northeast was relatively cool, and horse meat was easy to store. Find some deep wells where the ice and snow have not yet melted, and hang the slaughtered and washed horse meat in a huge bamboo basket and put it in the well, hanging in the air without touching the water surface, which can basically ensure a low temperature of five or six degrees above zero, and can be eaten for half a month after refrigeration.

No matter how long it is, ordinary soldiers and hungry people in these years don't care about being a little rancid. But Li Su would rather not eat it, and then he will be a vegetarian for half a month.

"While the horse meat is still fresh for a week, eat more horse meat and eat less, and after a week, you must be ready to be a continuous vegetarian." Li Su didn't want to open a small stove to be special, so he was thinking about it in his heart.

So as soon as he sat down, he picked up a piece of the horse's leg bone and gnawed it.

Liu Bei also gave him special preferential treatment, and this pot of horse legs was slightly put with cloves to remove sourness and cover the taste.

After seeing him gnaw off a horse's ankle, Liu Bei wiped his hands, took out a silk book from his arms, put it on the table, and discussed:

"In the evening just now, when the army was attacking and retreating, the head of the city suddenly sounded gold and chaos, and then shot a chirping hammer. The military marquis who pressed the formation felt that it was boring, so he picked it up, and there was a reply from Yan Rou to us on it. ”

Arrows are arrows that hollow out to form a bagpipe effect, and when fired, they emit a strange roar that attracts attention even on noisy battlefields.

At that time, the Xiongnu generation of male lord Mao Dun Shan Yu used the strategy of "Ming Di to kill his father" to kill the head Man Shan Yu to seize the throne. Therefore, the Hu people are very accustomed to using this kind of arrow.

Li Su was still a little surprised when he heard this: "Yan Rou actually replied?" What did he say? ”

As Li Su expected, he had a counter-plot of hitting a shot with dates or no dates, no matter what, it had to be Yan Rou who killed Nanlou, or Nanlou killed Yan Rou, there should be no third possibility.

Hu people know a fart scheme? Even if Yan Rou himself is not successful, Nanlou will definitely be suspicious, and Yan Rou predicts Nanlou's prediction, isn't this chain of suspicion established?

Liu Bei broke a root of the horse chop, and said while gnawing: "Roughly speaking, Yan Rou expressed his willingness to surrender, but his strength was insufficient, and he couldn't kill the difficult building, so he could only sacrifice the door - you wipe your hands and read the letter yourself." ”

Li Su took a general look at it and finally understood the ins and outs.

Li Su smiled: "This Yan Rou is okay, and he can still dodge our knife." Actually didn't kill two of them, but this kind of response is just a fraud, that is, to talk to the difficult building and the snake, and want to win the trust of the difficult building. He didn't really think we'd fall for it. ”

Liu Bei didn't take it for granted, and Zhengse said: "I was only slightly skeptical at first, since you said so, then there is no doubt about it." If it was a fraudulent surrender, did he want to besiege and kill our army after entering the city under the pretext of offering the door? ”

Li Su listened to Liu Bei's question so seriously, and at first felt that Liu Bei was making a big fuss and deliberately pretending to be a novice.

But after thinking about it, the pre-Qin and Han Dynasty battles are indeed quite rare precedents of this kind of deception and siege that can be used for reference. Li Su is tired of seeing those tricks from the Romance of the Three Kingdoms and the war examples of previous dynasties, and now he really hasn't systematically summarized them.

Li Su recalled the Romance of the Three Kingdoms, and when encountering this situation, Zhuge Liang generally ordered Zhao Yun/Guan Xing/Zhang Bao in advance, telling them that the enemy was surrendering by fraud, and the moment he opened the city gate, he cut down the enemy general who led the way, and then grabbed the door.

But this kind of is obviously written blindly by Luo Dai to pull the bias. If it was so easy to grab the door, Zhou Yu would not have been trapped in the urn city by the jack gate in Jiangling and shot by Cao Ren's crossbow arrows.

It is still necessary to think of some tactics in the long term to prevent the enemy from catching turtles in the urn.

After thinking about it, he wiped his mouth and asked clearly: "This north gate of Changli City, we have been attacking it for a few days, the city wall is straight, and there is no urn city?" What is Yan Rou trying to do? Without the urn city, you can only count on the jack gate, could it be that a trap is dug far away on the inside of the city gate in advance? Let the vanguard of our army steal the city, even if you pass through the city gate quickly, you can't rush into the main street of the city? ”

Liu Bei only listened to two or three sentences, and he had goosebumps slightly: Boya's reaction was too fast, and in a few breaths, he thought of the urn city, the jack gate, and the trap...... N more despicable means that the enemy may use.

This is a comprehensive enough summary, what do you usually think about?

Liu Bei immediately replied vigilantly: "When you say this, you really have to guard against it, the north gate of Changli does not have an urn city from the outside, but it cannot be ruled out that some urn cities are built on the inside."

Even if there is no one in peacetime, in wartime, a new earthen wall is temporarily rammed, leaving a narrow gap for pedestrians, which can have an effect similar to that of a simple urn city, and it has to be guarded against. ”

Li Su nodded: "Then our army will start cutting wood and building wells tomorrow, higher than the city wall, one or two are enough, and we don't expect to climb the tower and shoot arrows into the city to kill the enemy, as long as we can overlook the city and deploy defenses, even if Yan Rou temporarily builds a simple urn city, we can see it." If you want to dig a hole in the ground, the excavated soil will often be piled up nearby to form a low wall fortification, which cannot be invisible and traceless. ”

Liu Bei thought so and immediately ordered the army to prepare to build a well.

Li Su pondered, since there is no permanent urn city and a temporary urn city that is easy to guard, then Yan Rou's main reliance on deception should only be the jack gate.

How to prevent a jack brake alone, how to do it?

The easiest way, of course, is to find a strong man like Confucius and his father, and directly hold the city gate to prevent it from falling, and then the rest of the soldiers continue to charge and pour in-

The reason why Confucius's father, Shu Liang Su, was able to get the status of "doctor" was because when the Jin and Lu coalition forces attacked the city of Qianyang, the defenders lowered the gate, and Shu Liang Su raised his arms to buy time for the friendly troops who had already entered the city to retreat.

After the war, he was appreciated by the Lu nobleman Meng Sun, and rewarded his uncle Liang Su with a small fiefdom, so that he could find his little wife Yan Zheng and give birth to Confucius at the age of sixty or seventy.

However, Li Su estimated that although the strength of Dian Wei under him may not be smaller than that of Shu Liang Su, the weight of the city gate at the end of the Han Dynasty must have been much heavier than that in the early Spring and Autumn Period, and Dian Wei must not be able to bear it.

Manpower is not good, how about getting some support structures?

Li Su's thinking habits are from later generations, so he will naturally analyze them quantitatively.

Although he was a liberal arts student in his last life, he didn't know much about engineering calculations, but he still had common sense, and he had seen a lot of decorating houses, and he knew that the No. 12 steel bar generally used in the project must be no problem with a load of more than ten tons.

Why don't you urgently ask the blacksmiths in the army to make some iron rods that are one inch thick and support the city gates when the time comes?

However, the iron rod is too thin to easily get into the gate made of thick trees, and it is not necessarily in the right direction.

So, make a huge pallet at the upper and lower ends of the iron rod, increase the force area, and ensure that the city gate falls and falls on the pallet?

This is too large, and it is difficult for soldiers to carry it unknowingly, and it is easy to accept uneven collapse.

After thinking about it, Li Su quickly gave full play to the geometric thinking of ordinary middle school students and came up with a way to make a total of six iron rods, and the two ends of the iron rods were made into oblique slits like clothes forks.

When the time comes, all these iron rods are carried by the cavalry as weapons, and when they arrive at the city gate, they immediately secretly dismount and place them, insert them on the ground in groups of twos and twos, and finally put two horizontal resting on them, forming a "parallel bar" structure.

When the gate fell, it landed directly on the two iron rods.

I don't believe that the three-finger-thick steel bar can't withstand the Hercules' door.

So, Li Su immediately brought a pen and paper and drew a simple picture on the paper, while explaining to Liu Bei.

Liu Bei looked at the schematic diagram, and his eyes lit up instantly: Brother Bo Yaxian also has such ideas about strange tricks and tricks, and reacts so quickly.

"Okay, if you have this method, you won't be afraid that Yan Rou will put the gate and trap him!"

As soon as the two of them combined, they decided to make the "parallel bars" three or four feet high and long, which is about equal to three meters in later generations.

In this way, the cavalry rode on horseback, and the height would not exceed two zhang at most. The parallel bars are one foot and three feet high, which can ensure that after resisting the city gate, the cavalry can still sprint through at full speed.

And the lateral length is so long, and there is no fear of not aligning the position where the gate fell when placing obstacles in the dark - isn't the error of three meters enough to margin?

In addition, the iron rod of three or four feet is also more suitable for individual soldiers to carry at night - Zhang Fei's snake spear has eight zhang, and the cavalry holds these parallel bar accessories, in the eyes of the defenders of the city, maybe it is a weapon like a trident.

"In addition, if our army agrees too simply, maybe Yan Rou will suspect that we have seen through his plan to lure the enemy, and we will do what we want. It's best that we send another letter back to Yan Rou in the next two days, and make more difficult requests for him, so that we are very hesitant, so that even if we finally agree, it will appear that we are very cautious and sincere. ”

After discussing how to build the parallel bars of the door, Li Su added.

"Oh? What are some suggestions? Liu Bei asked with interest.

Li Su thought for a while: "I asked Yan Rou not to work hard to defend the city in the past few days, to allow our army to easily fill the moat near the city gate, and at the same time to allow our wooden donkey carts to cross the filled point and go to the opposite bank to destroy the sheep and horse wall and reject the horses." ”

Liu Bei twisted his mind and thought: "This is not easy to act, right?" Yan Rou would definitely refuse on the grounds that she couldn't fool the Overseers of the Difficulty. ”

Li Su: "We can make excuses for him, such as asking him to allow us to build a well and condescendingly release arrows at the head of the city, so that Yan Rou can use the excuse that 'the archers on the city wall are at a high disadvantage and dare not raise their heads to release arrows to suppress the Han army to fill the river'."

As long as Yan Rou pretended to be unable to think of how to counter our army's well chariot for a while, it would be impossible for Nanlou to think of it. And if Yan Rou wants to win our trust, he can only pretend that he can't think of it, and pretend to be suppressed by Jing Yan. In this way, even if his final lure to the enemy is not used, we will first abolish two or three fortifications outside the city, wouldn't we have the best of both worlds? ”

No matter whether Yan Rouzhong hits the plan or not, whether he stops in time or not, he will lose a lot of money.

"Brilliant plan! Just do what Boya says, and reply to Yan Rou tomorrow! Liu Bei almost couldn't help laughing wildly in his heart.