Orc culture is almost always semi-nomadic. It is not that the orcs do not appectaiet the benefits of civilization, but their religion, cultural tradition and society does not favour the creation and maintaning of stable states. Loyalty among orcs is not to a vague concept such as a nation, but rather to the the clan, the tribe and the family, in that order.
Only loyalty to orc-kind itself ranks higher but orcs see intertribal warfare as a way of getting rid of weakness and they only rarely unite for anything bigger than a particularly grandiose raid.
When orcs conquers a civilized land, they want to live the good life that civilization provides but their ways will almost invariably mean that after a generation or two, they start squabbling over tribal matters and/or expend the assets of the conquered land. After this, virtually inevitable, entropy sets in, the orcs are ousted by rebels, outer enemies or simply move on for another place to take over, returning to their old lifestyles.
Among orcs, status is everything and every orc, no matter how lowly, defends his or her position in the tribal pecking order. And all seek to rise in status where possible. No orc follows an order from a superior without at least whining, or making a symbolic challenge. This is not seen as dishonorable or strange, but is actually appreciated. An orc chief who needs to use cunning and brutality to keep his followers in line is seen as admirable, since his tribe is obviously filled with warriors who dare to questioning him. Likewise, to get a beatdown or be intimidated by a mighty chief is not seen as a disgrace for the recepient either, but rather an acknowledgement of ones position.
Gender roles among orcs are not particularly enlightened. Females are for breeding and are in general supposed to tend to the young, keep the camp running and otherwise shut up. This is not to say that females are seen as worthless in any way and all orcs fight fiercely to protect the dens and warrens where the females and young are housed. Females are not forbidden to become warriors or even chiefs, but they fight very much uphill and will have to work a lot harder than a male would.
Those rare orc females who make a name for themselves as chiefs or warriors are almost always extremely conservative in their outlook, seeing their rise to power as proof that the system works and the opposition as proof that they are truly worthy rulers.
Orcs, contrary to common stereotypes, do not hold arcane magic in any particular disdain. Although they do recognize it's usefulness and power, it just happens to be difficult for the orc mindset to learn much of the arcane arts. Magic coming from the gods is easier to come by and easier to understand.
The ruler of any given tribe is always the mightiest warrior, whether a raging barbarian or a cool-headed fighter. Priests and oracles serve as advisors and are held in high regard, as are the clever and sly ones who serve as assassins and scouts. No matter how mighty a rare wizard or ambitious assassin might be, if they proclaim themselves chiefs they will eventually find themselves abandoned by their people or slain.