The army at the start of the campaign
On the 15th of August, 1916, the following units were mobilized : The Supreme HQ, 4 Army HQ's, 6 Corps HQ's ; 2 cavalry divisions, 23 infantry divisions, 1 border guard brigade, 5 calarasi ( Romanian for light cavalry ) brigades ; 2 heavy artillery brigades, 1 regiment and 1 battalion of mountain artillery, anti-aircraft artillery with 113 guns ; 1 regiment of engineers tasked with railroad building, 1 regiment of bridging engineers and 1 special battalion with a ballooning company ; the airforce ( it consisted of 4 under strength squadrons ) and the navy's "Danube Flotilla" ( 4 monitors, 8 torpedo boats plus several other gunboats and small ships ).
Adding up all the numbers, the army had ( on paper ) 366 infantry battalions with 574 machine guns, 104 cavalry squadrons with 40 machine guns and 374 artillery batteries. The numbers were quite impressive, but the reality was somewhat different. Only 3 infantry divisions were actually mobilized right after the declaration of war; of the 366 battalions, just 146 were regular units, 120 were still to be raised whilst the rest of 100 were mainly militia units, made up of men in their late 40's or early 50's. Altogether, 833601 men were mobilized, 19843 of which were officers and NCO's. 75% of the forces made up the "operational army", whilst the rest were reserve units. Therefore, the fighting units comprised 551057 soldiers and 11890 officers and NCO's. 600000 additional men were not mobilized, but held in reserve, though they could still be called up.
According to the pre-war theories, the most important thing was considered maneuver and rapid attack. For this reason, the Romanian infantry division had limited artillery support. A typical division had 20 infantry battalions, 15 artillery batteries, 1 cavalry squadron and an engineer battalion, whilst a German division had 9 infantry battalions and 9 artillery batteries. Therefore, in terms of artillery the Romanian division was at an disadvantage. Also, because so many new units were raised in a short time, there was a serious shortage of officers and NCO's. A division of 27000 men was supposed to be led by just 640 officers.
The regular Romanian units were generally pretty well equipped when it came to the basic infantrymen, who had modern rifles. But there were not enough of them to arm all the units, so the militia had to be equipped with old rifles, mostly left-over from the 1877 war. Gas masks were something rare in those early days as well ; fortunately, gas attacks did not occur so the pending disaster didn't happen. Grenades were also rare and it seems that over half of the infantrymen had never even seen one before the war ! The worse was yet to come : there was a desperate shortage of machine guns, as 161 of the 614 existing machine guns were actually fixed weapons. The average infantry battalion had as little as 1-2 machine guns, whilst a German one had 5-6 heavy machine guns and 9 light machine guns. This inferiority plagued the Romanian units throughout the 1916 campaign.
Most of the artillery batteries were equiped with French built 75 mm Schneider Model 1897 guns and 105 mm Schneider howitzers. Both were modern artillery pieces, with a good rate of fire, well-suited to the requirements of modern warfare. Unfortunately, again there were not enough of them ( only 233 of 374 batteries were equipped with these modern guns ), so most of the puny 53 mm fortification guns were removed from their positions, fitted with improvised carriages and issued to newly-raised batteries. However, they were of limited use, as they had slow rate of fire and little effect. The heavy artillery was also improvised using guns taken from the forts of Bucharest, but again only a small number of pieces were actually available. As for mountain guns, badly needed for the coming campaign, just two of the 8 existing batteries had modern equipment ; the rest used obsolete or ( again ) improvised pieces. The AA artillery was entirely an improvisation, as all of its 113 guns were converted from field guns.
The airforce had between 40 and 50 planes, none of which was armed with machine guns. Furthermore, many of them were 2 to 4 years old and of limited use. There had been some attempts to introduce wireless telegraphy before the war, but nothing came of it. Only 57 pilots were available for operations in the first day of the war, but it was even worse when it came to mechanics : it seems that just 11 of them had to maintain all the aircraft ! During 1916, the airforce was limited to reconnaissance and liaison duties, although there have been some attempts to bomb the enemy positions.
In terms of ammunition and vehicles, things were even worse. Romania had little heavy industry which could directly support the war effort. In 1914, the army had an arsenal and a couple of small factories, which could manufacture some wagons, repair any existing weapons and produce a very limited amount of ammunition. Motor transport ( such as trucks ) was virtually unknown, except for a few cars reserved for high-ranking officers. Two years later and just a few days before Romania entered the war, inspite of all the efforts, the industry could ensure only 2 artillery shells per day for each gun and 1 cartridge per day for each rifle. Even worse, only parts of the artillery shells and cartridges were actually manufactured in Romania ; the rest had to be imported. From this point of view, the situation was extremely serious : the Romanian army would have to enter the war while still relying heavily on imports from the west. Since the only way these supplies could come was through Russia's huge territory and primitive rail network, it was obvious the army was going to have serious supply problems.
At the start of the campaign, the common Romanian soldier was very much willing to fight. Morale was high, as war was expected to be short, and the men were eager to liberate Transilvania and fulfil the dream of many generations. Regular army units were well trained, but the same thing cannot be said abut the hundreds of thousands of conscripts which were called up in August 1916. They had to learn the hard way, but many died before they could do so.
The officer corps was plagued manly by two problems : first, it was too small for the sudden expanse of the army, and second, it was fairely ignorant to the realities of modern warfare. The cavalry was still trained to charge the enemy, like 50 years ago ; the artillery was not used en masse, but rather spread out, and no attempt was made to study the effects of the artillery barrage. High-ranking officers were reasonably competent ( some, like general Eremia Gregorescu or major Ion Antonescu eventually proved to be excellent officers ) but some were awfully incompetent. One such example was the war ministry, general Nicolae Iliescu, who kept ensuring the government that the army was entirely prepared for war, that victory was certain, and so on. Naturely, at the start of the war the entire officer corps was inexperienced, but the situation improved as the war dragged on. Slowly, the grim realities of war ensured that the incompetent and cowards were eliminated, but this took time.