Topic:   Why I love the Percentile Based Table system   (Read 10549 times)


0 Members and 1 Guest are viewing this topic.

Silverwind


  • ^ This guy is amazing.

  • ****


  • Posts: 2805

  • For the glory of my maker
    • View Profile
Why I love the Percentile Based Table system
« on: April 26, 2010, 05:48:05 PM »
As most of you know, I've long regarded stat calibration as the most difficult task in game design. It has singlehandedly brought down several of my unfinished projects and sapped an unhealthy amount of motivation from the ones I did finish.

I used to spend countless hours writing and rewriting stat tables that never quite worked out when put to the test, and after almost three years of formulating these tedious number patterns I was no nearer to achieving a balanced stat table than I was when I began. If anything I was getting worse! Then, with a sudden spark of inspiration last February while working on the Roguesoft RPG Engine, I concocted the Percentile Based Table system.

Put simply, I love the PBT system. It's beautiful. It's the V6 of stat calibration. Not only does it deliver the balanced rates I've long sought after, it's also extremely versatile. Indeed, versatility is the driving force behind PBT in the form of distinctive entity characteristics. Whereas up until now most GM/SC RPGs (certainly mine) boast varying degrees of enemy strength, there's virtually no depth whatsoever applied to enemy characteristics. An enemy is either strong or weak, nothing else, and with such flat levels of versatility RPGs like Quest of Magic boasting vast amounts of combat fail to engage the player in any degree of skilfulness, as gameplay revolves solely around level grinding.

With PBT it's a piece of cake to define enemy strengths and weaknesses, and using the base value chart as a reference you can easily work out the overall strength of an enemy in accordance with its level. Furthermore it's incredibly easy to adjust the rates of battle damage, accuracy and duration to whatever you like without ever having to modify the system.

In short, the PBT system is one of the most beneficial game resources ever. If you haven't already tried it out, you're bound to fall in love with it like me.
« Last Edit: April 26, 2010, 06:43:14 PM by Silverwind »
I survived the spammage of 2007

Mystor


  • GMG-er

  • **


  • Posts: 696

  • I am the myst that consumes us all.
    • View Profile
Re: Why I love the Percentage Based Table system
« Reply #1 on: April 26, 2010, 05:52:14 PM »
Can I has link?
TYVM :P
"I'll lie to him."
"And if that doesn't work?"
"Then I'll tell the truth. We're allowed to do that, in emergencies. We can't plan for everything, you know."
   -Colonel Graff, Ender&

Silverwind


  • ^ This guy is amazing.

  • ****


  • Posts: 2805

  • For the glory of my maker
    • View Profile
Re: Why I love the Percentage Based Table system
« Reply #2 on: April 26, 2010, 06:03:45 PM »
The RSRPGE uses the PBT system. Check out the topic for the latest release: http://www.gamemakersgarage.com/cgi-bin/yabb/YaBB.cgi?board=gametime;action=display;num=1259869684;start=90#90
« Last Edit: April 26, 2010, 06:04:03 PM by Silverwind »
I survived the spammage of 2007

Mystor


  • GMG-er

  • **


  • Posts: 696

  • I am the myst that consumes us all.
    • View Profile
Re: Why I love the Percentage Based Table system
« Reply #3 on: April 26, 2010, 06:13:02 PM »
Only problem: I don't have a mac available right now...
"I'll lie to him."
"And if that doesn't work?"
"Then I'll tell the truth. We're allowed to do that, in emergencies. We can't plan for everything, you know."
   -Colonel Graff, Ender&

Gan


  • Administrator

  • ^ This guy is amazing.

  • *****


  • Posts: 4408
    • View Profile
Re: Why I love the Percentage Based Table system
« Reply #4 on: April 26, 2010, 06:20:51 PM »
I feel your pain...


-Gan

Silverwind


  • ^ This guy is amazing.

  • ****


  • Posts: 2805

  • For the glory of my maker
    • View Profile
Re: Why I love the Percentage Based Table system
« Reply #5 on: April 26, 2010, 06:21:01 PM »
Ah. Well here's the formula for battle calculation:

'--- Preset variables.
baseHitChance = 50
maxHitChance = 95
minHitChance = 5
baseDamage = 16
baseRandomDamage = 7
maxDamage = 999
minDamage = 5
 
'--- Determine the chance of the attack hitting.
hitWindow = baseHitChance
hitWindow = hitWindow + attackerAccuracy
hitWindow = hitWindow - defenderEvasion
IF hitWindow > maxHitChance THEN hitWindow = maxHitChance
IF hitWindow < minHitChance THEN hitWindow = minHitChance
hitRoll = RANDOM 100
 
'--- If the attack hits, deal damage.
IF hitRoll =< hitWindow THEN
 ┬ádamageRoll = RANDOM baseRandomDamage
 ┬ádamageRoll = damageRoll + baseDamage
 ┬ádamageRoll = damageRoll + attackerAttack
 ┬ádamageRoll = damageRoll - defenderDefense
 ┬áIF damageRoll < minDamage THEN damageRoll = minDamage
 ┬áIF damageRoll > maxDamage THEN damageRoll = maxDamage
 ┬ádefenderHP = defenderHP - damageRoll
END IF


And these are the primary attributes of an entity: (keeping to my template, but you can easily add your own)


entityAttack = 10
entityDefence = 10
entityAccuracy = 10
entityEvasion = 10


The combined attribute values of an enemy should equal 10 * the amount of its primary attributes * the enemy's level. So 40 for a level 1 enemy with 4 primary attributes.

Also, an enemy's HP should equal 100 to ensure correct calculation of the percentile based sum. You can set the player's HP to whatever you want to accommodate your desired vitality rate. For example, if I wanted the player to survive 4 monsters of equal level on average before getting defeated, I'd set the player's HP to 400.
« Last Edit: April 26, 2010, 06:38:21 PM by Silverwind »
I survived the spammage of 2007

Mystor


  • GMG-er

  • **


  • Posts: 696

  • I am the myst that consumes us all.
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #6 on: April 26, 2010, 06:56:57 PM »
Thanks, So basically it is all based around percentiles?
"I'll lie to him."
"And if that doesn't work?"
"Then I'll tell the truth. We're allowed to do that, in emergencies. We can't plan for everything, you know."
   -Colonel Graff, Ender&

Charlo


  • GMG-er

  • **


  • Posts: 451
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #7 on: April 26, 2010, 07:32:34 PM »
That code is nice.  I've tried implementing percentages into battle calculations but GM's lack of decimal support is hard to get around.  Your way is ingenious.  

Silverwind


  • ^ This guy is amazing.

  • ****


  • Posts: 2805

  • For the glory of my maker
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #8 on: April 27, 2010, 03:22:37 AM »
Quote
Thanks, So basically it is all based around percentiles?
Yup. :) If you'd like to give me some odds and rates for battle damage, attack accuracy and battle length I can show you how to set up a table.
I survived the spammage of 2007

Tireas Dragon


  • GMG Extraordinaire

  • ***


  • Posts: 1626

  • Trying to recover from my shattered screen.
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #9 on: April 27, 2010, 09:54:03 AM »
I try to stick with smaller numbers, and gain more health as you go up levels. So the first few levels increase your strength exponentially. I don't like it though I think I am going to try something else involving vitality and level.
I must be dreaming (wake up me wake up) How could this have happened. Tireas' cry when he found his computer fallen over in his chair with it's screen shattered.

Silverwind


  • ^ This guy is amazing.

  • ****


  • Posts: 2805

  • For the glory of my maker
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #10 on: April 27, 2010, 11:20:07 AM »
I used to work off raw numbers too, but trust me when I say it's a spiral of doom. The concept of percentage based calculation fixes all the problems down the line with progression rates.

The values themselves are no longer important, it's the table of values as a whole that matters.
I survived the spammage of 2007

EqwanoX


  • GMG Extraordinaire

  • ***


  • Posts: 1179
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #11 on: January 20, 2011, 11:39:24 AM »
i think its easier to just have armor+def subtract a fixed amount of hit points, better armor subtracts more.

how do you handle accuracy and evade stats? those are even more complicated to balance

Silverwind


  • ^ This guy is amazing.

  • ****


  • Posts: 2805

  • For the glory of my maker
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #12 on: February 04, 2011, 04:24:28 PM »
Here's a basic explanation of how the system works:

http://screencast.com/t/vtqow4k4mc

I'll gladly do another one (when it's not so late and my voice isn't so raspy) if there's anything else you'd like me to explain.

EDIT:

Whoops! The Medusa would have a 70% chance of hitting the player, not an 80% chance (50 + 30 - 10). Pretend you didn't hear that...
« Last Edit: February 04, 2011, 04:32:10 PM by Silverwind »
I survived the spammage of 2007

EqwanoX


  • GMG Extraordinaire

  • ***


  • Posts: 1179
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #13 on: February 05, 2011, 01:29:06 PM »
 thats exacly what i did in gangwars. i agree thats probly the best way to handle hit and evade stats

GMG Kurt


  • GMG-er

  • **


  • Posts: 682

  • Sorry for being such a noob
    • View Profile
Re: Why I love the Percentile Based Table system
« Reply #14 on: May 01, 2011, 08:37:28 PM »
personally I'm a fan of Thac0 like in AD&D. I'm currently starting an RPG that will use a lot of AD&D mechanics.
Just your average Weekend Warrior.
Yes I know I have bad spelling, it's what makes me such a good programmer!

"Old art, weather magnificent or wretched, is always the raw material of new art. The artist's job, though, is to