I believe that a game system is always better summarized in the character sheets it uses, and I'm not the only one who thinks so, as many rpg books begin with a brief description of them. Thus, I'm going to present the Arcade Ruleset first with an overview of what will be found in a character sheet (or a reference sheet for npcs or monsters).
Apart from the equipment and description sections, rules-wise a character sheet will have three main sections: combat, skills, and specialities.
The combat section will list some stats that will come into play in combat encounters. I'm talking such things as Hit Points (HP), Movement (MOV), Initiative (INI), Melee Attack Rating (MAR), Melee Defense Rating (MDR), Ranged Attack Rating (RAR) and Ranged Defense Rating (RDR). In the Ajsalium setting, two more stats will be added to govern magic: Mana Points (MP) and Magic resistance (MR). In the Necronomicon adventures HP will be joined by Sanity Points (SP), to discern the psychologycal impact of the mythos in the heroes. I think the names given to the mentioned stats are rather self-explanatory, but don't worry because I'll explain their use later.
The skills section will list some stats that rate how skillfull the character is in diverse areas. These have been selected to be very generic, so they can cover every possible situation, or be close to that goal. So far the list of skills is this: Fortitude (FOR), Agility (AGI), Perception (PER), Dexterity (DEX), Intelligence (INT), Sociability (SOC) and Knowledge (KNO). In case those names make you think of D&D, let me explain that it has been purely coincidental; I followed my own road, and just when I picked the names for the skills I realized this was so close to the famous D&D characteristics. Great minds think alike (or so I like telling to myself). Knowledge is a bit special in that it represents general knowledge, but for every point it has admits one concrete area of expertise (more on this later).
The specialities section is the one that will vary most from one setting to another, and the one that still needs most work. In the Ajsalium setting, this will include some special powers typical of fantasy rpgs, such as the cleric's prayers, the paladin's immunity to fear, a wizard's special link with his/her familiar, or tactical maneovers for fighters. In the Necronomicon setting, being a mainly investigative setting, this section will be filled with the areas of master expertise that will automatically provide the hints needed for the plot to advance; some examples would be forensics, intimidation, history, academical research or arts & crafts. In the Galaxtar setting, this section will list some specialized skills that further develop the generic ones, allowing the characters to perform some tasks in a way similar to the usage of skills, but with greater chance of success. Again, if you want more info on this just keep reading subsequent articles.