List of core mechanics

[herrozerro]

Savage worlds:
Roll skill or attribute (d4-d12) against a base target number of 4.

Add modifiers to target number, or in special circumstances other values may be target number (like parry for example).

If character is a wildcard roll an additional d6, take the higher of the two dice.

If a die comes up with its maximum value, roll it again and add the new value to the maximum.

 

[steenan]

Powered by Apocalypse (Apocalypse World, Dungeon World, Monsterhearts etc.)

Roll 2d6+stat (stats are in range -1 to +3):
6 or less: GM makes a hard move (a negative consequence that can't be avoided and must be dealt with). This can mean a failure in the task attempted, but does not have to.
7-9: Success with a complication or cost.
10+: Full success, no negatives.

Rolls are triggered by specific events in fiction. A mechanical resolution can't be attempted without meeting the trigger and it can't be ignored when the trigger is met.

Some "moves" (trigger+roll+results) are usable for everybody, some are character-specific.

Only players roll dice.

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Fate Core

Roll skill+4dF (Fudge dice: two sides with +, two with -, two blank). A roll may be against an opponent's roll or a static difficulty.

Aspects that may be invoked (for a fate point, +2 to the result or reroll all dice) or compelled (GM gives a player a fate point and introduces a complication based on the aspect; player may pay fate point to refuse).

Four types of actions: Attack (deal stress; stressed out character is removed from conflict), Create advantage (discover or create an aspect and gain a free invoke), Overcome (achieve a specific goal or remove a negative condition) and Defend (stop a hostile action).

Four results: failure, draw (partial effect or complication), success and success with style (with additional benefits).

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Cortex Plus

Create a dice pool by taking one die from each of several categories (eg. an affiliation, a distinction, a speciality and a superpower). Roll the pool and sum the two highest results. Compare to the sum of an opposing roll.

Each "1" rolled may be activated by the opposition with a Plot Point to introduce a complication.

 

[xrayzed]

ORE (One Roll Engine)

Roll n d10s, where n = skill + stat.

Look for matching numbers ("sets") of two or more numbers.

The number of matching dice is the width, with wider sets going first.

The number on the dice is the "height", which determines how effective the result is, higher numbers being better.

So a roll of 2,3,3,6,9 would give a 2x3 set (width of 2, height of 3).

 

[GMMichael]

D20 System: used in D&D 3.x and variants, this at it's basic core is a roll of d20+modifier vs. a Difficulty Class. Rolling equal or above the DC is a success.

This is a good mechanic. I've touched it up a bit.

Modos RPG: roll d20 + ability modifier + skill, versus an opposed roll.
- If the opposition is just difficulty, then the GM rolls d20 + difficulty.
- Equal rolls are ties. Ties can be rerolled, or treated as ties.

AD&D 2ed: attack rolls. To determine if an attack scores damage, an attacker needs a THAC0 and the defender needs an AC.
- Determining THAC0: class levels award THAC0, which stands for To Hit Armor Class 0 (zero).
- Armor and dexterity lower Armor Class.
If a character needs X To Hit Armor Class 0, then he needs X-Y To Hit Armor Class Y. Which is to say, roll X-Y or higher to hit armor class Y.

Simple, right? I've touched it up a bit.

Modos RPG: attack rolls. To hit your opponent, your attack roll (d20 + ability mod + skill) must exceed your opponent's defense roll (d20 + ability mod + skill). Simple. And directly related to the core mechanic above.

Dragon Age: attack rolls. Roll 3d6 plus strength plus focus. Beat the target's defense to hit. But if you rolled doubles, you get the number on one of the double-dice to spend in stunts. Stunts are, well, like critical hits, but more interesting.

Dark Heresy: nope. I won't even try. Because in this system, your success in attacking is based on your own ability, not the enemy's. But then the enemy gets a chance to defend anyway, not based on your roll, but on his ability. Or, um, I don't know. But the Inquisition is coming...

 

[Balesir]

Pendragon:

Roll d20 against an adjusted skill (generally in the 1-19 range, but could be modified higher or lower).

Any roll less than your adjusted skill counts as whatever you rolled, except that if your adjusted skill is greater than 20 you add any amount it is over 20 to the roll (e.g. if you have an adjusted skill of 24 in jousting, and you roll a 15, you count that as 15 + 4 = 19). The maximum you can count as a score is 20 (so the same jouster with a roll of 19 only scores 20, not 23).

Any roll over your adjusted skill counts as 0 (zero) score.

A roll that is exactly equal to your adjusted skill counts as a score of 20.

Highest score wins.

 

[ThirdWizard]

The Window

Skill competency is represented as a die - d4, d6, d8, d10, d12, d20, d30. The lower the die, the more competency the PC has at that skill.

This is a roll under system. A roll equal to or less than the target number is a success and anything above the target number is a failure. Average difficulty is 6.

 

[Psychman]

Advanced Fighting Fantasy

All tested actions use SKILL plus any appropriate special skill. Sometimes MAGIC substitutes for SKILL.

To test for simple success, roll under SKILL + special skill, modified for difficulty on 2d6. Critical is double 1, Fumble is double 6.

For opposed tests eg combat, roll 2d6 and add SKILL + special skill. Compare results, highest wins. Critical is double 6, Fumble is double 1.