BASIC D20 SKILL ROLLS
Many times in a role playing game, characters find themselves at odds with GM-controlled Non-Player
Characters (it’s true!). It must be noted that a family game such as Basic d20 frowns upon narratives
involving characters fighting to the death against humanoid monsters and collecting their various
treasures and assorted magical artifacts. Normal d20 rules describe how to resolve such unsavory
encounters as no doubt many uncouth and violence-loving “role players” will indulge in suchstorytelling. However, for a change of pace, basic processes for resolving other types of encounters aredetailed below to round out the otherwise combat-oriented ruleset presented in D&D and other d20games.

SIMPLE SKILL CHECKS
Simple skill checks simply consist of the GM setting a difficulty class for a certain action with the player
rolling a d20, adding one ability score modifier and one skill bonus to the roll and comparing this result
to the DC. If the result equals or is higher than the DC, the action succeeds. If it is less, the action does
not succeed.
Simple skill checks follow the following formula:
D20 + ABILITY SCORE MODIFIER + SKILL BONUS VS. DCStandard difficulty classes are shown below.
Difficulty
Very Easy
Easy
AverageTough
Challenging
Formidable
HeroicSuperheroic
Nearly Impossible

DC0510152025303540

Example (Skill Used)
Notice something large in plain sight (Awareness)
Climb a knotted rope (Athletics)
Hear an approaching guard (Awareness)
Rig a wagon wheel to fall off (Thievery)
Swim in stormy water (Athletics)
Open an average lock (Thievery)
Leap across a 30-foot chasm (Athletics)
Bluff your way past very wary guards (Interaction)
Track an orc across hard ground after 24 hours of rainfall (Wilderness)

To resolve a simple skill check:
1. The GM determines which ability score modifier applies.
2. The GM determines which skill applies.
3. The GM determines the difficulty class (DC) of the task.
4. The player (or GM) rolls a d20 and adds the ability score modifier and the skill bonus.
a. If the roll is greater than or equal to the DC, then the character succeeds.
b. If the roll is less than the DC, then the character fails.
5. The GM determines the result based on success or failure.

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OPPOSED SKILL CHECKS
An opposed check is a check whose success or failure is determined by comparing the check result toanother character’s check result. In an opposed check, the higher result succeeds, while the lower result
fails. In case of a tie, the higher skill modifier wins. If these scores are the same, roll again to break thetie.
Opposed skill checks follow the following formula:
D20 + ABILITY SCORE MODIFIER + SKILL BONUS VS. D20 + ABILITY SCORE MODIFIER + SKILL BONUS
Example opposed checks are shown below.
Task
Con someone
Pretend to be someone else
Create a false map
Hide from someone
Make a bully back down
Sneak up on someone
Steal a coin pouch
Tie a prisoner securely

Ability + Skill (specialty)
Cha + Interaction (bluff)
Cha + Performance (disguise)Dex + Thievery (forgery)Dex + Thievery (hide)
Str + Interaction (intimidate)Dex + Thievery (move silently)
Dex + Thievery (sleight of hand)Dex + Wilderness (use rope)

Ability + Skill (specialty)
Wis + Awareness (sense motive)
Wis + Awareness (spot)
Wis + Thievery (forgery)Wis + Awareness (spot)
Cha + Will
Wis + Awareness (listen)Wis + Awareness (spot)Dex + Thievery (escape artist)

To resolve an opposed skill check:
1. The GM determines which ability score modifiers apply (for both sides, they need not be the same).
2. The GM determines which skills apply (for both sides, they need not be the same).
3. Each side rolls a d20 and adds the ability score modifier and skill bonus for their side.
4. Success and failure is determined:
a. The side with the higher roll is successful, the side with the lower roll is unsuccessful.
b. In the event of a tie, the side with the higher overall modifier wins.
c. If there is a tie, and both overall modifiers are equal, then each side rolls again.

EXTENDED CONTEST SKILL CHECKS
The previous two forms of conflict resolution are standard for d20-based games. The “extendedcontest” also exists in d20-based games but is normally used only for combat. To illustrate this point,consider the rules for melee combat. The attacker rolls a d20 and adds the Strength ability score
modifier and the character’s Fight skill bonus. The difficulty class for this roll is the target’s Armor Class.
In this respect, an attack roll is just like a simple skill check. However, if the attacker succeeds on thisroll, the target does not immediately drop. The attacker then rolls damage and this damage issubtracted from the hit points of the target. If the target then attacks, the same procedure is used, withthe first attacker possibly suffering damage. In Basic d20, the Toughness skill is used to determine acharacter’s number of hit points (along with the Constitution modifier and Toughness feats). For the2

purposes of the following discussion, the Attack Bonus will be defined as the ability score modifier andskill bonus that is used for the “attack” roll. In melee combat, the Attack Bonus is Str + Fight + othermodifiers. The Defense Bonus will be defined as the ability score modifier and skill bonus that is usedfor defense plus 10. For melee combat, the Defense Bonus is the character’s Dex + Parry (or ArmorBonus) + other modifiers. “Contest points” will be defined as the ability score modifier and skill thatprovides the pool of points that are diminished as the extended contest continues as a result of“damage.” In melee combat, the contest points are known as “hit points” and are derived from Con +Toughness + other modifiers (like Toughness feats).
Now, let’s apply this same principle to a different form of combat. Let’s say you have a campaign set inancient Greece and the characters must frequently confront different philosophers in a forum andengage in debate. Instead of requiring a simple skill check for the PCs or even opposed skill checks withenemy philosophers, you, as GM, decide that it would be much more entertaining to treat theseencounters as combats with various possibilities for breaking off the debate before defeat along with
the introduction of special feats just for this campaign that give the characters various bonuses whendebating. Each round of debate will last for ten minutes and each philosopher gets the chance to makeone attack roll during this time. You decide that the Debate Attack Bonus for PCs is Wis + Knowledge
since the PCs are honest seekers of knowledge that do not resort to sophistry or verbal trickery to win
their debates. If they were of a different, more unscrupulous school of thought that relies on suave
oratory, he might allow them to use Cha + Interaction during debates. The PCs school of philosophy
relies on critical logical analysis to refute their opponent’s arguments, so the GM makes the Debate
Defense Bonus equal to Int + Awareness + 10. This is the “armor class” that is used during each round of
the debate. For contest points, each character has “credibility points” that diminish as they engage inphilosophical debate. In this case, when a character reaches zero “credibility points” he must concedethat his opponent has won the debate (or it could mean that he has nothing left to say, or that theaudience is not interested in hearing anything further from him). Credibility points are derived from
Charisma and Profession (philosopher). For each rank in Profession (philosopher) the character gains
1d6 + Cha modifier credibility points. Each successful attack does 1d6 + Wis in damage. Credibility
points are “healed” at a rate of one point per rank in Profession (philosopher) per week and no magic
can speed up this healing! Now, this example may not sound exciting to a normal role playing group,
but it does illustrate that just about any sort of extended conflict can be modeled with the d20 combat
system.
Another example would be two diplomats vying to sway a monarch to commit his forces to their
particular side in a war. The Attack Bonus could be Cha + Interaction (to make convincing statements
while following court decorum) while the Defense Bonus could be Wis + Will + 10 (to maintaincomposure and determination in the face of their opponent’s intrigue). The contest points are“influence points” and each diplomat gains 1d6 + Cha modifier influence points per rank in Profession(diplomat). Damage is equal to 1d6 + Cha for each successful attack. One combat round takes a day.
When one diplomat’s influence points drop to zero, he is effectively “dead” to that monarch, and may
be expelled from court. The GM can then determine the monarch’s response based on how many
influence points the winning diplomat retained.

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The relevant formulae for extended contests are:D20 + ATTACK BONUS VS. DEFENSE BONUS + 10
CONTEST POINTS = 1D6 + ABILITY SCORE MODIFIER PER RANK FOR SKILL USED AS CONTEST POINTSDAMAGE = 1D6 + ATTACK ABILITY SCORE MODIFIER
To resolve an extended contest:
1. The GM determines which ability score modifier and skill bonus will be used for the Attack Bonus.
2. The GM determines which ability score modifier and skill bonus will be used for the Defense Bonus.
3. The GM determines which ability score modifier and skill bonus will be used for Contest Points.
4. Combat takes place in rounds. Each round, each combatant has one chance to attack.
a. If an attacker succeeds during a round, the defender loses contest points.
b. If an attacker fails during a round, the defender does not lose contest points.
5. Once a contestant is reduced to zero contest points, the GM determines the result of the contest.

COMBAT AND CONTESTS IN BASIC D20First of all, there’s nothing wrong with having normal physical combat in a role playing game (especially
if there’s a possibility to get some treasure!). However, it doesn’t have to be the only way thatcharacters fight against adversaries. Sure, it’s a stretch and most gamers won’t be used to it, but
introducing other forms of combat into your game can really add some variety and give non-combat
oriented characters a chance to shine while using the standard conventions of d20 combat resolution.
Your computer hacker can wear down a system’s “firewall points” while trying to break into a
government database, one character can chase down a murder suspect while both are losing “fatiguepoints” during the run, your character can win a national election by doing enough damage to take his
opponent’s “campaign points” to zero. The potential types of extended contests are limitless.

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