Polemos is a game played primarily with the use of pencil, paper, and dice. You are the game master (GM)- you craft an imaginary world and tell an interactive story with the help of your players. They each control a character in the story, and you control everything beyond that. You should strive to be fair and consistent when applying rules in general, but feel free to bend or break, add or subtract from the rules given here or elsewhere. The enjoyment of your players should outweigh everything else.
As GM you will be responsible for determining the difficulty of skill rolls, as well as their results.
The following can be used for determining a skill roll's difficulty qualitatively. You may choose to tell your players these difficulties before they roll, after they roll, or not at all. As always you can adjust this based on your judgment. First choose a skill value based on the level of experience or knowledge required to do the task:
Then use a roll difficulty added to the skill value based on how difficult the task is for that experience level:
Alternatively, you may also choose to use a character's current experience level instead of a required experience level so that there is always some element of chance. Some examples:
It is perfectly valid to let players see skill rolls you make for NPCs, and to have knowledge on the roll totals for any and all rolls you make. However, in certain circumstances you may want to hide these rolls from players for dramatic effect. For example, if a player is disguised and passed by a guard, you may wish to keep tension high. You could hide the roll and not announce the total when the guard uses the test identity ability, so the player is unsure of whether they have been made or not. The fact that you rolled at all may tip the player off that the test identity ability was used, which may or may not be desirable. You can make assumed rolls (see section below) if you don't want players aware something happened at all.
Sometimes it is useful to not have a skill roll be performed with actual dice, but to assume some value was rolled for easily or secretly determining outcomes. This is usually called an assumed roll, and for 2D6 a roll of 7 is most commonly assumed, but you can assume any roll value you like. You can either announce the assumed roll and its results, or make a hidden assumed roll to keep player's unaware anything happened at all. For example, if an enemy has assassinated a player's NPC friend in the next room and you do not want to tip the player off by prompting them to use a perception ability, you can assume they rolled some number on their perception, and secretly determine if they noticed the assassination.
Dating in the 4th Age of Polemos is usually based on the AV calendar. For simplicity it is a solar calendar with 12 consistent months of 28 days, or four weeks each. While different cultures and locales have different names for certain months, days, and might use different calendars altogether, feel free to use names from our modern Gregorian calendar for ease of terminology. For example, while some may be interested it how you'd say AV831/04/18 in the land of Agothos, using "April 18th, 831" works just fine as well. If consistent 28 day months are tripping people up, it's also perfectly fine to use the modern Gregorian calendar for the length of months. In general, don't stress about dates being 'realistic' in-world; dates are difficult even without adding the unfamiliarity of a different calendar. Dates should help players reckon time (e.g. a hundred years ago, two weeks from now) and give flavor to the setting, and not become a minutia to confuse or argue over.
The 4th Age of Polemos takes place in the aftermath of a great breaking of the natural world through magic. One of the consequences of the Great War is that supernatural creatures are more common that future ages, particularly in the deep wilderness. Aggressive or territorial spirits, folk monsters like vampires, twisted versions of natural creatures, and other monsters are real and an ever-present threat that all communities deal with, to a larger or lesser degree. Because monsters ultimately trace their origin from the use of magic monsters in Polemos cannot be scientifically categorized. People in Polemos may seek to categorize and study monsters, or they may tell legends or build folk knowledge such as 'garlic keeps away vampires' but ultimately these are incomplete explanations and not canon you are bound to. Some spirits and monsters are described in the rules, but these are primarily given for inspiration. For example, the vampirism condition states that vampires don't cast a shadow, but you may wish for your particular vampire to not only cast a shadow but use it as a weapon. You are encouraged to treat each monster individually and to create new and exciting monstrous creatures, particularly for the players to fight against.
That said, for monsters that draw inspiration from our own world and pop culture such as werewolves or zombies, avoid misleading players against a monster because of assumed out-of-game knowledge. For example, try to avoid a situation where a player uses a silver sword against a werewolf but is quickly killed because they assumed your werewolf acts like werewolves from other settings. One way to accomplish this is to avoid direct naming schemes and descriptions that invite those assumptions - for example, you might call a creature 'a walking corpse' instead of 'a zombie' to avoid the assumption that you must destroy the head. Another way would be to give the players plenty of time to investigate or research the monster before facing it, time where you can give information that corrects any assumptions ahead of time. Yet another way would be to let players make use of their assumptions but make the consequences of failure light, so the player can learn from that mistake and try something else. Finally, you can simply remind players not to bring out-of-game assumptions about monsters if you hear them - for example, you might say "Remember this monster is not a movie zombie. It might need be destroyed some other way."
You are encouraged to make the traits and weaknesses of a monster fitting to your story and not utterly random. For example, you might be able to defeat a vampire by confronting its animal aggression with courageous determination, mercifully righting the wrong that caused its heartlessness, or even by indulging in some even darker power to overpower it, but you wouldn't want the key to defeating the monster to be an arbitrary act like jumping four times in a row.
Without GM support, players that have non-combat professions may feel that their investment in XP was not worth it. Thus you should be mindful that players with crafting ability have ample time and resources necessary to thrive, but not enough so they monopolize playtime. If you feel a character's profession would not fit well with your narrative, then players should be warned against investing in it, at time of character creation if possible. Some specifics to consider for supporting characters with trades:
The final ability of the art of alchemy deals with the creation of a Philosopher's Stone. The result of the ability will either be a worthy or distorted Stone with vastly different consequences, but the ability is intentionally vague and contradictory on how to produce a worthy Stone. Spoilers follow on the truth behind this ability so that the GM may decide how to integrate the ability into the story, or perhaps decide to prevent players from taking the ability.
In truth they only way to make a worthy Philosopher's Stone is to use no prima materia and to simply drink the lifeblood of a perfect being willingly given - an impossible task. This is intentionally deceptive to the player and reflects the underlying lore theme that alchemy's (and indeed all magic's) underlying assumptions are distorted at best or lies at worst. The inability of mortals to achieve immortality or perform other miracles is not a matter of simply trying harder or studying longer; immortality is something you are given, not something you earn.
The ability's uniquely difficult tier level and the ambiguity is intended to warn a player that the ability is incredibly risky and not fully understood by other alchemists. It is recommended that an alchemist character seeking to make a philosopher's stone should not seek it lightly, unless the characters's hubris is obvious. If the story supports it, the alchemist should be slowly and subtly seduced from simple chemistry into deeper symbolic truths of the world and introduced to the idea of the Philosopher's Stone as the ultimate culmination of symbolic magic - a way to grant wishes by symbolically modifying the created laws of the universe. This temptation increases as they learn more alchemy abilities, and either the story or the character should work out the details on how much prima materia and what kind of sacrifice to make. The alchemist, after creating a Stone, can be initially led to believe that they have created a worthy stone, only to have it 'flip' to tragedy at a narratively important time. This could be mere moments afterward, or a significant time later.
If the story does not support the themes and ideas for the Philospher's Stone and cannot otherwise be adapted to fit the story, the GM may simply not allow the alchemist to learn the ability. The character might learn that the ritual to create the stone is simply a tall tale, or otherwise still under research and not actually effective, or to learn it the ability requires knowledge that the character never ends up finding during the story.
In any case, the player should always have forewarning in some form about the risks and temptations of the Philospher's Stone - a player should never be caught off-guard when the Stone's truth is revealed or feel their character was 'wasted' without narrative payoff.