Ad Infinitum is still in development, so this area will be constantly changing as we progress in coding the actual system. Many of the examples used in describing the underlying rules of the gaming system take place in a fantasy setting. This is more for convenience (or perhaps lack of imagination) on the part of the author. As noted elsewhere, the initial release of ADI will include a sample world that is ready to play, and it will take place in a fantasy setting.

At present, the information contained on this page is a mix of information for the player and the world maintainer. That is, the users who will actually be playing in an ADI world, and the people who will set up, customize, and maintain such a world. There are no "spoilers", however, so feel free to read anything you are interested in.

The current maintainer of this document is Boris Mann. Please contact him with any comments or questions. As well, you might want to post to the Game System forum on the ADI Project page.

1. Preface
   Ad Infinitum, or ADI, is meant to be a complete gaming system. However, having said that, its extreme customizability makes it very easy to implement any kind of game you want. An ADI world could take place in a medieval fantasy setting, a secret agent campaign, or even a super hero environment. It is all a matter of adjusting the races and skills as you see fit. The core of the ADI system, which is based on nine ability scores, is pretty much the only part of the system set in stone.
   
2. Ability Scores
   The ADI system has nine ability scores. The nine abilities are further divided into three sub-categories, Body, Mind, and Spirit. The nine main abilities are determined by a random number (whose range is determined in the properties of your world - the default is between 3 and 18) plus a racial modifier. The three sub-categories of Body, Mind, and Spirit are determined by the sum of their component abilities, again plus a racial modifier. In general, the nine main abilities are set after character creation, with only magical effects or items causing them to change. The three sub-categories are more mutable. They serve as a power source for some skills, as well as an indicator of well-being in the three areas they are named for. They replenish themselves automatically over time.
   1. Body
      This score represents the physical aspect of the character. As such, any attacks that cause physical damage are applied to this score, even if the source of the physical damage was magical in nature. For example, a fireball spell's damage would be subtracted from the Body score, since it causes physical damage. Professions that focus on physical combat tend to have high scores in this area.
      1. Strength: pure muscle power. This does not mean that you've got bulging biceps - you might be thin and wiry with tendons of steel.
      2. Endurance: how much can you take? The ability to keep going, in a physical sense.
      3. Dexterity: speed, agility, nimbleness, flexibility
   2. Mind
      All things mental are contained in this score.
      1. Intelligence: sheer brainpower. Faced with the unknown, this will help you figure anything out.
      2. Concentration: focusing on the task at hand, and not letting outside influences distract you.
      3. Knowledge: some might call it book learning. Years of study (or experience) have resulted in this attribute.
   3. Spirit
      Abilities which come from the inner strength of the character are represented by this score.
      1. Willpower: this is the spiritual counterpart to the Endurance ability. Once you've exhausted your physical reserves, this is what makes you go on. Conversely, if you've got a low willpower, no matter what your physical state, you're more likely to give up.
      2. Intuition: some call it a sixth sense, or maybe a hunch or gut feeling. Some facet of your unconsciousness that pokes its head up and tries to tell you something every once in a while.
      3. Charisma: an inner spark. A lot of this will make you a born leader. No one can put their finger on exactly what it is about you, it's just a certain something, which you either have or don't have.
         
3. Races
   Races are another way to change the flavour of an ADI world. They consist of a name, a description, a set of racial modifiers, and possibly racial skills. These modifiers may be positive or negative. The modifiers are applied at character creation time to the nine main ability scores, as well as the three sub-categories. Finally, some races may include racial skills, which you may choose to purchase for your character at creation time.
   
4. Skills
   Perhaps one of the most important things about ADI is that virtually everything is based around the concept of skills.
   
5. Magic
   Like most other abilities in Ad Infinitum, magic is just another skill. Actually, spells are broken into a variety of different groups, and you must possess a particular spell group skill to cast spells from that group. In addition, spells have a difficulty level, so you must possess a certain minimum skill level to cast spells. Everyone is able to cast the lower level spells of a group, but the aspiring magic user must truly specialize in order to master the higher level incantations.
   1. Who can use magic?
      Well. everybody has the possibility to use magic, but good scores in Mind or Soul will help you learn magic skills. If you don't have good ability scores in these areas, then you will suck at magic. Sucking at magic may lead to disastrous consequences.
   2. What is magic powered by?
      Each spell has its own power requirements, but the main power sources are a character's Mind and Spirit scores. A character must have enough reserves of Mind and/or Spirit left to satisfy the power requirements of the spell they are trying to cast. As mentioned earlier, Mind and Spirit scores replenish themselves over time. As well, they may be rejuvenated through the use of items found in the game.
   3. Do I have to use magic?
      You may choose to run a campaign where there is no magic. Perhaps it is a current day secret agent campaign, or maybe a far future world where technology rules. No problem. Since magic is merely a set of skills, you can simply define your local skillset to not include magic.
6. Professions
   There is no such thing as "character classes" that you may be familiar with from other gaming systems. All development in ADI is skill based, so any character may conceivably have any skill. As a starting point in character creation, you may choose to select a profession, which is a pre-packaged set of skills that fit together. For example, there might be a profession of Hunter, which would start with skills in trap-setting, fletchery, and bow use. The profession might also suggest certain minimum scores for abilities that are valuable to that profession.