'Middle Ages' are generally understood as a period of almost 1000 years, so the subject is quite complex. In the following entry I'll limit myself to High and Late Middle Ages, focusing on Germany, Poland and England.

In general, weapon ownership was quite common. There were no rules preventing anyone from possessing any kind of weapon or armour and anyone could have commissioned any type of weapon at the local craftsman, provided the latter was able to make it (your average rural blacksmiths were usually able to make a spear tip, but not a high-quality sword) and the customer could have afforded the commission, what was not always a given, as peasants had relatively little money to spend, especially in earlier part of the Middle Ages when the weapons and armour were relatively more expensive than in 14th or 15th century. In short, every free man had an access to weapons, although some could not have afforded most of them. With the low social mobility and relatively small size of the settlements, people living in a city district or a village were usually forming a well-knit community, where people knew and often helped each other, as the well-being of community was directly tied to their self-interest.

In many cases such possession was actually required by law, though. For example, English Assizes of Arms require each free tenant to have a specified weapons and pieces of armour, depending on their wealth. The Assize of Arms of 1181 issued in the name of Henry II stipulates that 'every burgher and every freeman shall have a gambeson, an iron hat and a spear' what was a bare minimum for all free people (although 'burgher or freeman' usually meant the head of the family), while 'those who have possessions or rents worth at least 16 marks shall have an armour, a helmet, a shield, and a lance'. Clergymen were generally exempt from all such considerations. Assize of Arms of 1242 issued in the name of Henry III stated that 'the citzens, burghers, free tenants, villeins and others aged 15 to 60 should convene and their be assessed what they should bear in accordance to their land and property, to wit: whoever possesses land worth 15 pounds - one armour, iron hat, sword, knife and horse [...] (who possesses) less than 10 marks but more than 40 shillings - falxes, knives, guisarmes and other small arms' (this section contains ten different wealth classes, I included only first and last for brevity's sake). Given that 40 shillings was a relatively small amount of money when applied to personal wealth, it meant that even relatively poor people were expected to have some form of military weapon, with the wording giving assumption that it was supposed to mean 'any weapon one can afford', including common tools, such as axes or hammers. Enea Piccolomini, later Pope Pius II, who had served as a pastor in several German states noted in 1444 that every 'respectable household', no matter whether rich or poor, was armed adequately to the means available and that Germans show high skill in using said weapons.

In medieval cities, the defense forces were primarily composed of the militia, and thus the edicts of the city councils often required the burghers to possess weapons. This was usually limited to people possessing a real estate withing the city walls, but the required equipment could have been quite costly (although not excessively so). For example, according to the edict issued by the city council of Wroclaw in 1290, every owner of a real estate within a city should possess 'bow or crossbow) while a Prussian land regulation of 1410 required all Prussian burghers to possess equipment composed at least of mail shirt, breastplate, kettle hat, plate gauntlets and a crossbow. Those who were found to not possess the required equipment were subject to a fine (although one could not borrow their weapons and armour under penalty of confiscation and additional fine). Control was usually conducted by the city councilmen and high-ranking craft representatives (owners of the real estate in a city were largely craftsmen or merchants united in craft organizations). An interesting thing is that some Polish cities required citizens to actively train in the art of shooting (e.g. prince Bolko of Świdnica issued such law in 1286) with shooting contests being a common occurrence, much like in contemporary England renowned for its archers. In 14th and 15th century, winners of such competitions often were either provided with new weapons and armours or were given a monetary equivalent if the already possessed them.

Now, people were able to possess weapons, but in cities they were generally not allowed to carry. Specific regulations varied from place to place, but in German cities in 14th and 15th century councils usually forbade carrying of all 'swords and long knives'* either at all or only after dusk, usually under penalty of weapon confiscation on top of a relatively small monetary fine or a jail time of several days. Carrying any form of weapon (even a dagger or a knife) into a church or to any formal meeting (e.g. that of craftsmen in a guildhouse) was often strictly prohibited.

*A city council edict issued in 1394 in Koenigsberg stated that no burgher is allowed to carry a knife longer than one ell within the city walls (we also need to remember that German word 'messer' could have meant either a common, table knife, or a large weapon, essentially a short sword).