D20.00 Basics (D20.00 Decimal Rules Supplement)
From D&D Wiki
Simply put, d20.00 is a system that, while similar to d20, is also using decimals. The reasons for why I thought of this as a good idea was that placing decimals in a system such as this would provide for more degrees of chance, as well as a little more "Realism," to the game through having actions not so easily attainable. It would also bring a few more shades of grey to what is usually a black and white system. While there seems to be nothing different about having simply having the same chances for hitting a certain number, the decimal system allows for more variability than just with a normal d20. Since every number has the same chance of being hit, and since there are now 1980 more possible hits to choose from, the chances of hitting a certain number, while the same, is not so guaranteed, because there are many more possibilities that the die can roll upon, not just a few. In practice, this usually results in numbers that are lower than the norm, which makes it less possible to obtain a certain result. Thus, with this, actions are no longer so easy to accomplish as the player has more probable possibilities that are less certain than before, and, is quite less cinematic than with a simple d20. For instance, on a normal everyday d20, you have the average of every roll coming out to 10.5, while with a d20.00, you have the average being a 10.005. Since the possibilities of getting a 10 or higher is lessened by at least 100% from 10.5, the probability is lowered closer to the point of nil (an impossibility, but can still be somewhat negated). Thus, with that, the possibilities of getting a success with every die roll is closer to the almost-perfect 1:2 probability of a coin, without negating variety.
Another helpful thing is that every creature can be quite more varied in what they know, as in skills. You can divide skillpoints more effectively to represent greater and lesser known skills. Another thing is that it makes things harder for people to figure out NPC stats, since instead of trying to guess their number in a simple single digit fashion, they have to get closer and closer to the numbers that the monsters have, making things more difficult for people to guess what those creature's stats are. Furthermore, this can also prove into the favor of the NPC, since they can more effectively hide their general stats, as well as having a possible unknown edge when they are close to the "Shear point" of whether they succeed or fail on an attack or the like.
The Problems of the implications with using this system are in quite a number. Because of the issues with Decimals and normal die which everyone would have in real life, you'd need to use a program that generates random numbers. Thus, this, until it has been finished, will only be in the realm of possibility of using Computer random number generators. Possible ideas for Number Generators would include:
- Ti-Program Die Generators
- RPG Systems such as OpenRPG  or TableGenie
Another problem is also the issue of willing players. With decimals, it seems that people get a bit scared around them, thus this ruleset is for those willing to try new things; thus, it is recommended to not be used that often, as people faced with this have shown a bit of annoyance at this variant ruleset.
Changing the d20 system to d20.00...
NOTE: This requires the use of a random number generator or a program which does numbers in excess of 1000 random numbers. Open RPG is preferred.
Basic mechanics: In order to get decimals (which requires a random number generator that can do up to the 1000's), you need to roll a die that is 2 times greater than what you are rolling for (like if you roll a d20, you roll a d2000). This comprises both your main numbers, and your decimals. To get to the base number, you then divide your result by 100, which gets you your answer.
(NOTE: For Open RPG, you cannot go higher than 1d10000. It is impossible. You have to use only the 10ths decimal place...)
Using real die
Because of the implications of the sizes needed for a d20.00 (essentially a d2000), another route is needed to roll these numbers in real life. Thus, it would be best to use existing dice in order to work around this. For now, this will be updated as ideas are made. As this isn't perfect, rolling like this will take more time as well than with the use of ORPG.
For now, Conversions of dice will be expected.
d10 ==> d10.00
to make a d10, a similar approach is needed. Simply use a d(0-9) [this is a normal single digit d10) and a d%. The d(0-9) is the normal numbers, while the d% is the Decimals. As with the d20.00, a roll of the d(0-9) equalling a 0, as well as the D% rolling a result of "0-00," equals a perfect 10. Otherwise, a d% roll of "0-00" always is rerolled.
Different colored d(0-9) and d% are incouraged for this, as to not screw up rolls.
d20 ==> d20.00
You'll need a d20 and a d100 (2d10 if needed). You file or clean off the 2 on the "20" face, leaving the numbers 0 through 19 on the dice. You roll this for the single digits. The d100 is then used for the decimals, with the 100 side (0-00) equalling a reroll, unless the d(0-19) rolls a 19, in which a roll of 0-00 makes the roll a perfect 20. In every other case, the d% always equals 1-99, with a roll of 0-00 being rerolled (again unless the d(0-19) also rolls a 19).
d4 ==> d4.00
to be added...