Civilization, broadly speaking, is held together by the collective agreement of a population of pokémon to place their fighting instincts aside and put social dynamics and cooperation first. Unprovoked battling within a town is looked down upon as a violation of that unwritten social pact and will generally get you branded as a criminal if it goes too far.
Outside of civilized areas, priorities are different. Colloquially known as “wild” or “feral” pokémon, those who choose not to or are unable to live in a town are rarely literate or numerate and typically behave according to the rule of the fittest. For wild pokémon, if you can beat another pokémon in a fight that gives you leave to make the decisions for the both of you. Strength earns respect and fear in equal measure, and even when small social groups arise the position of leader is typically determined by who can rough the rest up the best and thus changes often as power dynamics shift, such as when evolution creates or negates a type disadvantage.
Wild pokémon can be difficult to integrate into society proper. Largely unfamiliar with the concept of blanket peace across a larger social circle than one’s immediate pack, they tend to be distrustful of or derisive towards pokemon who choose to live in towns. For a pokémon who has learned to solve every problem with a battle a town may represent a frightening mass of strangers who are suspiciously tight-knit or a group of weaklings who deserve to be raided. Townsbuilt around the practice of dungeoneering, such as Glimmering Port, are especially frightening to most ferals due to the sheer number of experienced and powerful combatants who consider them home.
Earning the trust of a wild pokémon can be difficult, but it’s not impossible. Conventional wisdom states that the fastest way to make a wild pokémon listen to you is to beat them in a straight battle, and the fastest way to make a wild pokémon trust you is to give them food afterwards.
Wild pokémon tend to rely on Mystery Dungeons just as much as civilized pokémon, if for different reasons. Mystery Dungeons provide a relative amount of shelter and usually contain useful resources such as food, especially in the case of orchard-based dungeons. Many (but not all) of the pokémon that can be found in less dangerous Mystery Dungeons are ordinary wild pokémon.
See also: Dungeon Pokemon