I mostly play d&d-like d20 systems and d100 systems like Call of Cthulhu or Warhammer and I like both families for different reasons. Recently I had an idea how to combine them in hopefully interesting way.
Attributes range from -90 to +90 and are simply added to each d100 roll that uses them. I'd probably steal D&D attributes with minor changes (something like Strength, Coordination, Reflex, Constitution, Intelligence, Wisdom, Empathy, Will).
Each action/reaction you do you use 2 attributes - first for success roll and second for effect roll (but you roll just once - the roll for effect uses inverted digits from the roll for success).
Instead of skills, attacks, spells, saving throws etc. there are just actions and reactions of different types. Whenever you make action on an opponent he can choose one of matching reactions (if he knows any that match).
For example:
action: Punch
type: unarmed nonmagical melee attack
to succeed: Coordination
to effect: Strength
effects:
< 0: 1 points of bludgeoning damage
< 50: 2 points of bludgeoning damage
>= 50: 3 points of bludgeoning damage and knocked prone
reaction: Dodge Melee
works on: nonmagical melee attack
to resist: Reflex
to effect: Coordination
effects:
< 0: you dodged
< 50: you dodged and can move by 1 hex
>= 50: you dodged and can throw your opponent prone onto any nearby hex
reaction: Block
works on: nonmagical unarmed melee attack
to resist: Coordination
to effect: Constitution
effects:
< 0: you take half the damage
< 50: you and opponent both take half the damage
>= 50: you take 0 damage and opponent gets half the damage
attacker and defender both roll d100 and add their relevant attribute, whose result was higher - succeeds and his effect happens. The winner inverts digits in his d100 roll and adds the relevant effect attribute to see what the effect was.
If opponent doesn't do any reaction - action succeeds automatically but you still roll for effect.
Effects doesn't have to be 3 possible options, it can be more with different ranges, or even formulas for damage:
action: Firebolt
type: ranged elemental bullet spell attack
to succeed: Coordination
to effect: Will
effects:
result/10 points of fire damage, minimum 1
reaction: Counterspell
works on: spell
to succeed: Will
to effect: Intelligence
effects:
<0 : spell is delayed till next round
<30 : spell fails but oponent regains the spell slot
<60 : spell fails
>= 60: spell gets casted but you determine the target
When you do rolls without opponent for stuff that would be skills or attribute rolls in D&D (climbing, perception, strength, etc.) DM sets the opposing target number and possible effects. Default difficulty is 50 and default range for effects is <0 / <50 / >=50 with effect for <0 usually being "success but at what cost" and >=50 "critical success".
There's also possibility of stored rolls. When you hide or craft an item or prepare a trap - you roll for success and effect normally and it gets stored in that item/trap/your stealth. Then when the thing is triggered - your stored roll is used against the target.
What do you think? Is it too complicated? I like the fact it's fast (2 rolls for any action/reaction pair and it's split between DM and player so it should happen faster than rolling for to hit and then for damage). It's also quite flexible and consistent. And nonmagical characters have stuff to learn in late game and meaningfull decisions to make instead of "I do 3 attacks again". But that's just theory.
Attributes range from -90 to +90 and are simply added to each d100 roll that uses them. I'd probably steal D&D attributes with minor changes (something like Strength, Coordination, Reflex, Constitution, Intelligence, Wisdom, Empathy, Will).
Each action/reaction you do you use 2 attributes - first for success roll and second for effect roll (but you roll just once - the roll for effect uses inverted digits from the roll for success).
Instead of skills, attacks, spells, saving throws etc. there are just actions and reactions of different types. Whenever you make action on an opponent he can choose one of matching reactions (if he knows any that match).
For example:
action: Punch
type: unarmed nonmagical melee attack
to succeed: Coordination
to effect: Strength
effects:
< 0: 1 points of bludgeoning damage
< 50: 2 points of bludgeoning damage
>= 50: 3 points of bludgeoning damage and knocked prone
reaction: Dodge Melee
works on: nonmagical melee attack
to resist: Reflex
to effect: Coordination
effects:
< 0: you dodged
< 50: you dodged and can move by 1 hex
>= 50: you dodged and can throw your opponent prone onto any nearby hex
reaction: Block
works on: nonmagical unarmed melee attack
to resist: Coordination
to effect: Constitution
effects:
< 0: you take half the damage
< 50: you and opponent both take half the damage
>= 50: you take 0 damage and opponent gets half the damage
attacker and defender both roll d100 and add their relevant attribute, whose result was higher - succeeds and his effect happens. The winner inverts digits in his d100 roll and adds the relevant effect attribute to see what the effect was.
If opponent doesn't do any reaction - action succeeds automatically but you still roll for effect.
Effects doesn't have to be 3 possible options, it can be more with different ranges, or even formulas for damage:
action: Firebolt
type: ranged elemental bullet spell attack
to succeed: Coordination
to effect: Will
effects:
result/10 points of fire damage, minimum 1
reaction: Counterspell
works on: spell
to succeed: Will
to effect: Intelligence
effects:
<0 : spell is delayed till next round
<30 : spell fails but oponent regains the spell slot
<60 : spell fails
>= 60: spell gets casted but you determine the target
When you do rolls without opponent for stuff that would be skills or attribute rolls in D&D (climbing, perception, strength, etc.) DM sets the opposing target number and possible effects. Default difficulty is 50 and default range for effects is <0 / <50 / >=50 with effect for <0 usually being "success but at what cost" and >=50 "critical success".
There's also possibility of stored rolls. When you hide or craft an item or prepare a trap - you roll for success and effect normally and it gets stored in that item/trap/your stealth. Then when the thing is triggered - your stored roll is used against the target.
What do you think? Is it too complicated? I like the fact it's fast (2 rolls for any action/reaction pair and it's split between DM and player so it should happen faster than rolling for to hit and then for damage). It's also quite flexible and consistent. And nonmagical characters have stuff to learn in late game and meaningfull decisions to make instead of "I do 3 attacks again". But that's just theory.
