On the march the Legionary could carry between three and fourteen day's worth of rations, a saw, a wicker basket, a piece of rope or leather, a shovel, a waterskin, a sickle and a pickaxe.
Each of these items, aside from the pickaxe which was worn on the belt, was carried on a forked pole introduced by Gaius Marius call the pila muralia, which earned his men the nickname Marius' Mules.
There is some discrepancy over what was actually carried and the possible total weight. Some items at times may have been transported in wagon trains or on mules such as the legionaries' tents and millstones for grinding the corn rations.
It's been estimated that a Legionary could carry anywhere from 66 lbs. (30 kgs) to over 100 lbs. (45 kgs) of gear and weapons.
The gear and weapons with basic descriptions follows:
Buccellatum and Frumentum Hard tack and corn rations.
Papilio Leather tent.
Tunica The standard tunic worn over linen undergarments and underneath his armor.
Bracae While Romans considered the wearing of pants or trousers to be against any standard code of dress, legionaries in cold climates were allowed to wear wool or leather skin tight trousers that reached just below the knee.
Caligae Heavy military sandals that used iron hob-nails as treads, similar to modern day athletic cleats. The leather thongs continued half way up the shin and tied there, and in cold weather could be stuffed with wool or fur. Eventually these would be replaced by a heavier style of actual boot. Caligae was also the term from which the Emperor Gaius (Caligula) got his nickname. He was the son of the enormously popular Legate Germanicus and accompanied his Legions on several northern campaigns. As a boy the Legionaries saw him as a good luck mascot and called him Caligula for "Little Boots".
Balteus or Cingulum Militare The standard belt. Was rather narrow and were decorated with bronze strips, that were sometimes tin-plated, all the way around.
Focale Scarves worn to keep the metal of their armor from scraping their necks.
Galea Helmet. Though there were many types this was the most common helmet, the Imperial Gallic along with the Imperial Italic. They were generally made of bronze with iron trim, with a projecting piece shielded the neck and a smaller ridge fastened at the front for protection of the face. At the sides were large cheek pieces hinged at the top.
Sporran The apron consisted of a number of leather thongs to which were riveted metal plates, and weighted with bronze. It could have been either decorative, protection for the genitals or a combination of both.
Scutum The large Roman shield, which was curved to fit the body. They were made from thin sheets of wood, glued together so that the grain of each piece was at right angles to the piece next to it. The whole was bound around the edges with wrought iron or bronze and the center was hollowed out on the inside for the handgrip and protected by metal bands. On the outside the surface was covered in leather, on which was fastened gilded or silvered decoration, probably in bronze. Each cohort had different color schemes aid recognition during a battle. The shields also carried the name of the soldier and that of his centurion. On the march, the shield was hung by a strap over the left shoulder.
Lorica Hamata Chain mail that was used extensively throughout Roman history and well after its fall. It provided excellent protection and flexibility, but was very heavy and time consuming to make.
Lorica Segmentata Plate Armor. A name translated by modern scholars, as we don't know what the Romans actually called it. This armor was made up of many pieces of laminated iron all bound together to form a very flexible, strong and the most effective of Roman body protection. It seemingly replaced chain mail as the favored Legionary issue but due to budgeting constraints its length of service seems to have been a relatively short period of time (roughly Rome's golden era in the early empire and through the late 2nd century)
Loricae Squamatae Scale Armor, actually translated to Armor of Feathers. Scale armor consisted of row upon row of overlapping bronze or iron scales, which resembled a coat of feathers. Scale seemingly began to replace Plate late in the 2nd Century CE, as it was easier and less expensive to make than the other forms, but was less flexible and is often considered far less capable. Common thought is that it was especially vulnerable from an upward stab, but this theory is highly debated.
Gladius The Roman short sword. It was a double-edged weapon about 18 inches long and two inches wide, often with a corrugated bone grip formed to the Legionaries hand. A large round ball at the end helped with the balance. The primary use was for thrusting at short range. It was carried high on the right hand side so as to be clear of the legs and the shield arm.
Pilum The Roman javelin. It was seven feet long and very light, as it was thrown before just prior to engaging the enemy in melee, to disarm as much as wound them. The top three feet were of iron with a hardened point. It is probable that more sturdy types of spear of the same name were available for defense against cavalry in formation such as the turtle.
Pugio The Roman dagger was anywhere from 7 to 11 inches long in similar width to the gladius. It could be highly decorative or very plain, but was a very useful secondary weapon in case of being disarmed. It was attached to the belt on the left hand side.
A centurion's equipment was notably different from that of a legionary. He wore a transverse, side to side, crest along his helmet that would serve as an easily recognized point of reference for the men. The crest was made either of feathers or horsehair and colors could signify various ranks. Rather than the Lorica Segmentata of the Legionary, they would wear either chain or scale. It was generally about waist length with a lower edge similar to the muscled cuirass. The armor and helmet could be silver-plated as well. He did not wear the apron like the Legionary but had a double-pleated kilt like piece. They also wore a cloak, of fine material, which hung from the left shoulder and a very ornate belt.
Additionally the wearing of bronze greaves on the shins set them apart from the rank & file. They generally wore their swords on the left and daggers on the right, opposite of the common soldiers. They carried a Vitis, vine staff, in his right hand as a symbol of his rank. It was made of grapevine and about 3 feet long.
Officers could, of course, dress very differently from anyone else and there seems to be set pattern to the styles. They did have very fine dyed cloaks of various colors to signify rank. They generally wore a muscled cuirass and used a parazonium instead of a gladius; both described below.
Lorica Musculata The muscled cuirass was a bronze chest piece made in two pieces, one for the front and one for the back, and buckled together at the sides. These were well decorated with animal, mythological and chest muscle designs.
Pteruges Straps that hung off the shoulders and waist and covering the upper arms and legs, were made of leather. They were implemented to protect the arms and legs, while conserving the use of metal.
Parazonium The more ornate sword carried by officers, the hilt of which could be in the form of an eagle head, or lobed. It can be slung on a narrow shoulder baldric but is more often simply cradled in the left arm, and the fingers of the left hand can be forked over the lobed pommel.