Lv: Overall level of power
HP: Health Points
MP: Mana Points
Strength: Physical Strength. Used for melee attack and defense.
Dexterity: Physical Dexterity. Used for aim, some evasion, crits
Reflex: Reaction Speed. Used for some aim, some evasion, order turn in battle.
Magic: Magic/Willpower ability. Used for Magic and Willpower.

Phys Defense (PD): ( ( Strength * .66 ) + Equipment PD )
Phys Attack (PA): ( Strength + Equipment PA )
Mag Defense (MD): ( ( Magic * .66 ) + Equipment MD )
Mag Attack (MA): ( Magic + Equipment MA )

Accuracy: Phys: ( Dexterity * .66 + Reflex * .33 )
Mag: ( Magic * .66 + Reflex * .33 )
Evasion: ( Strength * .25 + Dexterity * .5 + Reflex * .25 )

Damage Dealt: ( ( ( Attacker Attack power * Crit bonus ) - Defender Defense power ) * any Final Damage bonuses )

Crit Rate: Attacker accuracy - Target evasion = Crit %, only applies when Attacker accuracy >Target evasion
Critical Hits deal 2x damage before Defense calculation, unless otherwise specified.

Hit Rate: Target evasion - Attacker accuracy = Miss %, only applies when Attacker accuracy < Target evasion

All stats have flat boosts applied, then percentage boosts applied, after any stat/equipment calculations.

General Etiquette
Out in the field, Adventurer parties generally stay out of each others' way. If two parties meet, they exchange info and see if their tasks are related. If so, parties often work together to accomplish the goal, assuming they aren't both competing for the same resource or objective. Rarely there's a clerical error and they're given the same request, but those are exceptions.
If the two have unrelated tasks, then it's considered common courtesy to share any warnings of nearby dangers if they know any, then just move on and get back to their own requests. Aside from those inter-party unspoken rules, intra-party rules are pretty much entirely up to the discretion of the party themselves.

Combat Roles
In terms of combat role distribution, it's unsurprisingly slanted towards the flashy glorious roles. Damage dealers; mages, willpower fighters, sharpshooters, swordsmen, the whole spectrum. People like feeling cool, and a lot of these roles leave them safe in the back lines.
Right behind the damage dealers is tanks and pullers. Tanks are heavily armored warriors that can defend the party and pull aggression from monsters to keep the rest of the group safe. It's a dangerous role, but a relatively simple one to pick up. Good tanks are a dime a dozen, great tanks are rare. Pullers are similar in role to tanks, but they use agility and speed to dodge and aggravate enemies, distracting them, instead of taking hits and fighting directly. Both can halfway fill a damage dealer role, but need to prioritize survival over attacking, so are more of supplements in that respect. Pullers are rarer than tanks, but fall into the same general category of helping the group survive.
Less common are the support units. Most often casters of some kind, they almost always know healing magic or willpower, and often have some other skills to buff their allies or debuff enemies. Larger groups will sometimes have dedicated healers and buff/debuffers, but smaller groups will often just have one person for both roles. Generally, if a small ( or even medium if the healer is dedicated ) party gets into a situation where one healer can't keep them healthy, they're in over their heads anyway.
Least common of all are non-combat members. It's rare to see a person in a party who can't actually contribute in a fight, but sometimes you need to bring someone along for whatever reason. Or maybe their skills are valuable enough to be worth defending them.

Overview of Magic and Willpower
Magic and Willpower both function on two basic systems; Mana control and Sequence formation.
Mana control, like it sounds, is the user's ability to control mana in their body, mana being the energy that is converted into magic, which affects the physical world. The core skills of Mana control are to sense it, move it in and out of the body and other objects, and push it through a magic sequence.
Sequence formation has to do with creating a magic sequence, a magic construct made of a small amount of mana that converts the mana pushed into it into physical actions, or sometimes into different magical actions. Being able to form sequences means you can choose how the magic takes shape and what it actually does.
The key difference between Magic and Willpower is which system they work on. Magic and mages work using Mana control, while Willpower and Will practitioners use Sequence formation.

Mages have their spells pre-defined, and after invoking a recorded spell sequence in some way pour their mana into it to cast a spell. They tend to have great control over their output and can cast magic with very specific effects, but their flexibility is low, since they need to spend time "learning" or "acquiring" spells, and can only cast the exact spell that they've learned. Simpler, lower level spells get imprinted upon a mage's soul after a certain amount of practice casting it while something or someone else forms the sequence, or with the help of a few uncommon devices and techniques can be directly imprinted with no practice.

Willpower users on the other hand make their sequences on the fly, crafting a new, unique sequence with each use of their power. After formation, they connect the sequence to themselves and the mana in their body naturally flows into the sequence, "casting" the Will technique. In contrast to mages, they have very poor mana control and generally cannot even move mana in and out of mana stones by themselves. Instead, they can use their powers basically as they see fit. Instead of being restricted to the same spell every time, a Willpower user can vary the shape, size, intensity, duration, and behavior of a move basically automatically. The downside to this is that they are limited to much more basic sequences, without intense training. A mage can just learn a spell with complex behavior once, and can then cast it as much as they want. A Willpower user would have to create that complex behavior from scratch every time they wanted to use it.

Learning New Spells
To learn a spell, you need to have someone or something that knows it create the formation, and then take over the cast and use your own mana to finish the spell repeatedly, until your soul memorizes the spell formation on its own, and you can cast it without an external aid in forming it. Usually this is done by a magic stone or device, since those are easy to use; just put your mana into it and the magic casts. Though, a mage can also form the spell and let someone else cast it, which is a bit trickier but still doable.

Madosa
My home town! Giant port city made of several large islands and many small islands lashed together and built on. Almost all land is covered in various buildings. Adventurer Central, home to the Madosa Adventurer Academy and Adventurer Guild Headquarters. Has just about any kind of shop or craftsman I could need. Might need to seek out experts for any some crafts though, Madosa shops mostly deal in mainstream, not high end.
The area is pretty heavily patrolled and hunted by lower level Adventurers and by the large number of ships constantly passing through. The monsters roaming freely around here are generally limited to some larger species of fish, around the size of a person, and an aggravatingly persistent but surprisingly useful island completely infested by slimes.
There are a couple places on the edges of Madosa's territory that have an eye kept on the monster population, letting it flourish but still keeping it in check. Those are generally used as training grounds though. One is populated by various beast type monsters, and if I recall the current local Boss of those is a bipedal wolf beast. The other has earth and water elementals constantly forming on it, good for practice against non-living monster types.