Converting d20 to single roll d%

[garrowolf]

I have one dice roll per action in my system. One dice roll covers everything from attack to damage and defense. What you do is set the damage instead of having a damage roll. Then your margin of success over the defense of the target adds to the base damage.
All magic has an error range which varies based on how skilled you are with magic and other conditions. Rolling an error is an automatic failure. Errors are usually 1-4 at most and 1 at the least. The larger the error range the greater the negative effect of a 1 or you have additional kinds of backlash.
Rolling a crit (18-20 depending on how well you are with magic) will increase your roll by +5 or you can spend the crit on a special effect.
I wouldn't switch to a percentile dice. They are slower to calculate with and D20 covers the same dice probabilities.

 

[marli]

I like your system, itseems to have a lot of the mats worked out in the design.

I wouldn't switch to a percentile dice. They are slower to calculate with and D20 covers the same dice probabilities.

they are slower IF you are doing any calculating in game. if however all the calculations are done before hand it takes 0 game time,
in that case d% offer better granularity plus the loads of random results.
for example 9 on a d20
is 41 to 45 on a d%
its also 1 result where the single digit exeeds the double digit(20%)
1 where it matches(20%) and 3 where it is less(60%)
you get 5 flip results of wide varity 14,24,34,44,54(producing 5 potentally different results in a seperate check/result)
you get 5 numbers that 50% of all possible rolls on that dice(1.2.3.4.5)

on a D20 you get......a 9.

which mean in D&D(as an example) you roll 1 or two dice,(maybe choose highest?) add or minus 1 or two other number, check your result, roll 1+ dice, add them up and add more numbers then check again.
and because all this maths happens in YOUR turn most players cant do ANYTHING in other players turns to speed things along.

 

[prosfilaes]

Ok seems I cont peak anyones interest in this matimatical conundrum

It's not a mathematical conundrum. The mathematical answer is simple; you can't replace a die roll then a choice followed by another die roll with one die roll.

With a d% you get lots of results of a single roll
You get d% of course
you get double digit d10(which relates closely to the d%)
you get the single digit d10
you two d10s to compare (matching, higher, lower)
you also get reverse percentile (31 and 39 are become 13 and 93)

It gives you a lot of maths to work with to produce a fast system.

With D%, you get 100 possible results. That's all. In Nomine's d666 provides an argument that treating this as other then a simple linear progression might have potential, but ultimately I suspect that anything else is going to be more work then it's worth. And at that point you're far from mathematics; you want someone to design you a system.