There were two components to the offensive. Project 14 was a ground assault and Project 17 was a artillery bombardment. From 2 to 27 April 1984, China had conducted the heaviest artillery barrage since 1979 against the Vietnamese border region, with more than 60,000 shells pounding 16 districts in L?ng Son, Cao Bang, Ha Tuyen, and Hoàng Lien Son Provinces. 256 artillery pieces bombarded the areas with 414 targets being allegedly hit. Decoy ground attacks were used in an attempt to lure PAVN forces into the open so the artillery could hit them. This was accompanied by a wave of infantry battalion-sized attacks on 6 April. The largest of them took place in Tràng Ð?nh District, L?ng Son Province, with several Chinese battalions assaulting Hills 820 and 636 near the routes taken during the 1979 invasion at the Friendship Gate. Despite mobilizing a large force, the Chinese were either beaten back or forced to abandon captured positions by the next day. Chinese documents later revealed that the ground attacks primarily served the diversionary objective, with their scales much lower than that reported by Western sources.

The PLA launched their assault on Laoshan at 05:00 on 28 April after intense artillery bombardment. PLA forces were estimated to outnumber the size of PAVN ones. The PLA 40th Division of the 14th Army crossed the border section to the west of the Lô River, while the 31st Division took Hill 1200 on the eastern bank. The Vietnamese defenders, including the PAVN 313th Division and 168th Artillery Brigade, were forced to retreat from the hills. PLA troops captured the hamlet of Na La, as well as Hills 233, 685 and 468, creating a salient of 2.5 km thrusting into Vietnam. These positions were shielded by steep cliffs covered by dense forests along the Thanh Thuy River, and could only be accessed by crossing the exposed eastern side of the Lô River valley. In roughly the same timeframe, the PLA conducted a similar operation on Zheyinshan, a nearby hill range east of Laoshan.

Fighting remained continued in other places such as Hills 1509 (Laoshan), 772, 233, 1200 (Zheyinshan) and 1030, over which control constantly changed hands. Although the hills were eventually secured, the performance regarding Laoshan was considered poor by the PLA. Factors such as bad timing, not considering terrain conditions and lack of flexibility between subordinates and officers lead to the assault being behind schedule with losses exceeding expectations. However unlike Laoshan, the performance for Zheyinshan was much better as the commanders allowed more flexibility and postponed the attack by an hour to let troops rest longer after heavy rain delays . Liao Xilong was the commanding officer and was promoted for his achievements.

The battle paused on 15 May, as Chinese forces had virtually secured these eight hills. Chinese records show 939 Chinese soldiers killed as well as 64 Labourers as of that date. After 15 May, the PLA started building defense fortifications on the hills.

The PAVN planned to retake the eight hills in a counteroffensive operation known as the MB84 Campaign. Military leader such as Le Tr?ng Tan, Le Ngoc Hien and Vu Lap gathered at Ha Giang to come up with a plan. They were assisted by Soviet advisers. The 313th Division which was the original defense force during the initial assault would be replenished. Additional infantry and artillery regiments from other Divisions were sent to provide additional support to the 313th Division. With this the PAVN that was outnumbered during the initial assault of Laoshan now was believed to have force size superior to the PLA in the region.

The first main counteroffensive was launched on 11 June with the target being the hamlet of Na La. However PLA defenders managed to hold off the attack. In late afternoon on the same day, a second attempt was made which was once again repulsed. Precise artilitary fire was considered one of the main reasons for the PLA's successful defense. The PLA recently imported Cymbeline radars from the United Kingdom which allowed it to locate the PAVN artillery. PLA forces were strengthened but the defensive positions were changed so there were fewer troops in key locations with the rest kept behind lines ready to provide replenishment.

On 19 June, the PAVN sent additional troops to support the MB84 Campaign. Troop size was said to have reached 40,000. In addition from 12 to 22 June, more than 30,000 artillery shells and 2,000,000 bullets were provided. On 5 July, a Dac Cong/Sapper unit from the PAVN 821st Sapper Regiment attacked the site of a Cymbeline radar resulting in 11 casualties (1 loss and 10 injuries) for the unit while inflicting 49 casualties (9 losses and 40 injuries) on PLA forces. It was reported that only the battery unit was damaged and the radar was restored to combat ready capabilities soon after. Nonetheless, the attack reportedly alarmed Deng Xiaoping, who ordered reconnaissance units to be deployed extensively.

The second main counteroffensive was launched on 12 July. This time not just the Hamlet of Na La but also multiple hills (1030, 233, 685, 300, 400) were targeted to be assaulted at the same time. This would be considered the largest Vietnamese offensive operation since 1979 Sino-Vietnamese War. However once again despite the large number of troops charging to take the hills, the PLA artillery firepower was too much for the PAVN forces. The counteroffensive lasted more than 18 hours. On that day Chinese records, put PAVN casualties at 1,080 but Chinese intercept of Vietnamese communications traffic led officials to revise the number to 3,000.

To defend the captured area, the PLA stationed two armies in the Vi Xuyen region, consisting of four infantry divisions, two artillery divisions, and several tank regiments. Chinese artillery positioned on the hills included 130 mm field guns, 152 mm howitzers, and 40-barrel multiple rocket launchers, while infantry regiments were equipped with 85 mm guns and 100-D mortars. The PLA used tanks in some of the battles. Other equipment that helped the PLA forces included Night Vision Goggles and target finding radars. This allowed PLA to locate hidden or resting PAVN soldiers under darkness as a cover and fire artillery on their positions. One of the most important factors to PLA success is "rear service" which was a logistics system. This system allowed over 120,000 artillery shells to be shipped to the frontlines. As a result PLA artillery units could fire at enemy positions without ever worrying about running out of ammunition. Despite the PAVN also heavily relying on artillery, they did not have this system leading to ammunition shortages.

Afterwards, fighting was gradually reduced and by end of July, active fighting had stopped to become sporadic artillery duels and skirmishes. PAVN commanders called off the attack due to heavy casualties and ammunition shortages. According to U.S. intelligence reports, Vietnamese forces failed to retake the eight hills. As the result, the PLA occupied 29 points within Vietnamese territory, including Hills 1509 and 772 west of the Lô River, as well as Hills 1250 and 1030 and Mount Si-La-Ca in the east. Along the 11-kilometer border segment, the deepest Chinese intrusion was made at Hills 685 and 468 located approximately 2 km to the south.