April 01, 2004

Nuclear Beasts Rules

Welcome to the Nuclear Beasts Rules Blog. The rules below have been largely divorced from the setting, so that readers can concentrate on the system itself. While it's not a wholly generic system, the rules should be flexible enough to accomodate a wide variety of settings.

The system was originally inspired by Ironclaw, but it's picked up elements of Savage Worlds, D20, numerous freebie RPGs, and, of course, my own ideas.

There are Designer's Notes scattered throughout the text, usually at the end of an entry. If you've got Javascript completely disabled, you may not be able to see them.

Posted by Kiz at 11:49 PM | Comments (0)

April 24, 2004

The Basics

Nuclear Beasts uses pools of dice to represent most game traits. Character attributes (ratings that all player characters start with) always consist of a single die and range from d4 to d12. Higher (or lower) ratings are simulated by adding a bonus or penalty to the rating.

Skills are also represented by pools of dice and will often consist of multiple dice. For example, a pool of 2 twelve-sided dice and a six-sided die could be written as (2d12,d6) or 2d12 & d6.

The "level" of a die is how big it is. A d4 is considered level 1, a d6 level 2, a d8 level 3, a d10 level 4 and a d12 level 5. The level of a skill or other pool of dice is the sum of the levels of all its dice. Thus a rating of (3d6) is level 6, the same as a rating of (d12,d4), (6d4), or (2d8). This isn't used much, but it's good to know.

When performing a task, it's common to roll a single attribute and a single skill together. All of these dice are pooled together and rolled at once. The largest number rolled is the result of the roll. Dice are never added together unless the rules specifically say so. You'll normally use the highest single die as your result.

If a bonus or penalty is applied, it modifies the final result accordingly. For example, (3d6)+2 would indicate that you roll 3d6 and add 2 to the highest result, giving you a possible range from 3 (all three dice rolled 1, plus 2) to 8 (at least one die rolled a 6). The +2 is called a bonus because it's a positive number. If it were (3d6)-2, then the -2 would be considered a penalty because it reduces the final result. The parentheses aren't really necessary (you always add the bonus to the final result, even if it would normally only apply to part of the roll), but are included for clarity.

Attributes and skills are often represented by just their name. For example, you might be called upon to roll Muscles & Speed. That means that you roll your Muscles die and your Speed die and take the highest number rolled. Any bonuses or penalties that apply to one rating in a test will always apply to the final result. For example, let's assume that you had a Muscles rating of d12, a +1 bonus to all Muscles rolls (due to some special trait such as being unnaturally strong) and a Speed rating of d6. If you were called upon to roll Muscles & Speed, you'd roll (d12,d6)+1. Even if the d6 ends up rolling the highest number, it'll still get the +1 bonus, despite the fact that the +1 was associated with your Muscles trait.

If there are multiple traits involved in a test that have bonuses or penalties attached to them, apply them all. If the same trait is being included in the test multiple times, you'll include any bonus or penalty associated with it multiple times, too.

Note that the more dice you have available to perform a given task, the more reliable your results will be. The larger those dice are, the more difficult the task that you can accomplish.

As you get more and more skilled, your average result will move up towards 12. It is possible to roll above 12 (see The Rule of Twelve below) but it's very rare and requires an extremely high skill.

Posted by Kiz at 09:41 PM | Comments (0)

The Rule of Twelve

There is one special rule that allows the highly skilled to occasionally produce really extraordinary results. When you roll more than one natural twelve (that is, the die actually rolled a 12, ignoring all modifiers) on your dice, you get a +4 bonus for every additional twelve rolled.

Note that this can only occur when you've got at least 2d12 in your pool. If you roll 4d10 and get all 10s, your result is still a 10. Only multiple 12s give you the bonus.

Example: Oloki the Caretaker is rolling Speed & Melee to try and hit someone and he's so fast and skilled that he's actually rolling (3d12,d8) in total. He rolls 6, 12, 1 and 12. Because he had two natural twelves, he gets a +4 bonus, bringing the total to 16. If he had any other bonuses or penalties, they'd be added to or subtracted from 16.

So basically, if you roll 2 natural twelves your result will be 16; if you roll 3 it will be 20, et cetera.

Posted by Kiz at 09:42 PM | Comments (0)

Character Creation

To create a character for Nuclear Beasts, you'll have to go through several steps. These are listed below in the simplest order, but you should be able to do them in any order you desire.

  1. Choose a breed for your character. This is their species. There are a bunch to choose from, from three different generations. You should take a good look at their stats and limitations before making up your mind. In particular, the first generation of Beasts didn't have hands!
  2. Assign your attributes. Note that the breed that you chose may adjust or restrict your stats.
  3. Pick your starting Edge(s). An Edge is a special ability or gift that modifies your character in a positive way.
  4. If you want some additional Edges, you'll have to take some matching Flaws to compensate. Flaws are like Edges but they make your character worse in some fashion.
  5. Pick one or more Drives if you want them... a drive is a special trait that motivates your character but can also hamper them. Drives are optional. You are limited to (at most) one major drive and up to three minor ones, but you don't have to take any of them at all if you don't want to.
  6. Buy your starting skills. Note that the breed you chose will give you certain skills for free, but you can increase those too.
  7. Pick a name, description, gender and otherwise fill in your character's background.
    Posted by Kiz at 10:10 PM | Comments (0)

Character Attributes

There are six Attributes or Stats used in Nuclear Beasts. Each of these will consist of a single die and be rated from d4 to d12. Values above and below these limits are simulated by adding special bonuses or penalties later.

Musclesyour strength, build and sheer muscle power.
Gutsyour personal constitution and overall health.
Speedyour agility, dexterity and general speed of movement.
Perceptionthe keenness of your senses; includes your ability to aim ranged attacks.
Brainsyour mental prowess and general education and knowledgability.
Spirityour strength of personality; affects willpower, social skills, and any psychic powers.

At character creation, you'll get a pool of 6 dice for your attributes. One die should be assigned to each attribute. You have your choice of 2 starting pools.

  • Normal: 1d10, 2d8, 2d6, 1d4
  • Generalist: 3d8, 3d6
The "typical" rating in an attribute is d6, so starting characters are a bit above average.

Posted by Kiz at 10:48 PM | Comments (0)

Stat Checks and Similar Tests

Occasionally, you'll need to roll a test that only affects a single stat. Since rolling a single die is a bit too random (particularly for things like tests of strength), we use a Stat & Stat test instead. Basically, to roll a standard check for any attribute, roll that attribute's die twice.

For example, you might roll Muscles & Muscles for a test of pure strength and muscle power, such as lifting a heavy object or arm-wrestling.

If you have a bonus or penalty that applies to a stat that's included in a test multiple times, you should apply that adjustment multiple times, too. The most common case for this is being Big or Small.

Example: Jumdro the Elephant (d6 Muscles, Big +2) is arm-wrestling Kiolo the Mouse (d10 Muscles, Small -2). Since this is a straight Muscles & Muscles test, Jumdro rolls 2d6+4 (because he has a +2 bonus to his Muscles rolls, applied twice) and Kiolo rolls 2d10-4 (because of that -2 penalty from Small, applied twice). So Jumdro can roll from 5 to 10 and Kiolo's range is -3 to 6. Despite the fact that Kiolo is in much better shape than his opponent, he'll need a lot of luck to overcome Jumdro's enormous mass.

There are also three common combination tests.

NameStats IncludedPurpose
Survival TestMuscles & GutsRolled to resist physical harm, including poisons.
Reaction TestSpeed & PerceptionRolled to notice and react to something in time. Also determines Initiative in combat.
Willpower TestBrains & SpiritRolled to resist pain or temptation, as well as some psychic powers.

Note that there are some Edges and Flaws that modify Survival, Reaction and Willpower tests specifically, so while your pool of dice will start as listed above, it might be different in play.

Posted by Kiz at 11:06 PM

Edges and Flaws

An Edge is a special trait that your character might possess. It might indicate an exceptional attribute, unusual aptitude for a particular skill, or an ability that most folks don't possess. If you want your character to possess a psychic power, you'll need to take the Psychic Power Edge.

A Flaw is basically the opposite. These traits endanger or inhibit your character in some way.

Unlike skills and attributes, Edges and Flaws generally aren't represented as pools of dice. You either have a particular one, or you don't, although some of them are available at different strengths.

Both traits are generally rated as either Minor or Major. In general, a Major Edge or Flaw is considered twice as strong as a Minor one. Technically, there are two additional levels: Trivial means that the Edge/Flaw is so minor that it's hardly worth charging any points for, while a Dramatic Edge/Flaw is so strong that it's generally reserved for non-player characters.

You start with your choice of one Major Edge or two Minor Edges. If you want more, you can take another Minor Edge and a Minor Flaw, or an extra Major Edge and your choice of one Major Flaw or two Minor ones to make up for it.

Some Edges and Flaws are Restricted however, which means that they're normally only found in specific breeds. If your breed starts with that Edge or Flaw, you get it automatically; otherwise, you can't take it at all.

Don't worry if you want more Edges than that; you'll be able to purchase more with your experience points during play.

Posted by Kiz at 11:59 PM | Comments (0)

April 25, 2004


There's a third category of special character trait: the Drive.

A Drive is something that motivates your character very strongly. This can provide benefits in certain cases, but it can also hamper you. If you don't want to start with a drive, you can pick one later or just not have one.

When a drive helps motivate you, you'll get a +1 bonus to appropriate tests. If the motivation is especially strong, you get a +2. Similarly, whenever you go against your drive, you get a -2 penalty... and if you're really violating it, the penalty climbs to -4. If you ever seriously violate a drive in a major way, you're liable to either lose it permanently or suffer minor penalties until you do something to atone for your actions.

Some example drives are listed below.

Loyal to X: your character is extremely loyal to a particular group or organization. You feel that it is your duty to serve and protect them. This grants a bonus to tests that directly involve the object of your loyalty, so you'll be better at defending it and at friendly social skills used with other members of the group. Whenever you engage in an act that your organization wouldn't approve of, though, you will suffer penalties and will generally be wracked with guilt.

Honest: your character abides by a personal code of honor. This entails always telling the truth and never engaging in deceptive actions unless there's a really good reason. You get a bonus to social rolls with folks who know you (because they know that you are always truthful and upright) and a bonus to resist any attempts to make you break your word. You're penalized whenever you do attempt to deceive folks, even when they deserve it.

Honorable: your character follows a warrior's code. You hate treachery and unfair fights. While you may lie or deceive folks if the situation calls for it, you will always keep your solemn oath. You get a bonus to social rolls with folks who know you (because they know that you are honorable) and to attempts to coerce you into doing dishonorable things. You're penalized when you do try to do something dishonorable.

Self-preservation: the drive of confirmed cowards, a character with this drive is primarily concerned with protecting their own hide. They get bonuses when fighting defensively, when fleeing from danger, and when desperately trying to persuade someone not to harm them. They get really nervous and incur penalties to their actions whenever they choose to take unnecessary risks. Unlike most drives, Self-preservation rarely causes you guilt if you seriously violate it; you're much more likely to simply lose the drive.

Charitable: a very selfless drive, your character has a soft heart and a weak spot for the unfortunate and downtrodden. You get bonuses when trying to help the less fortunate without more than token compensation. Such characters generally can't hold onto money and have trouble ignoring the misery of others. They suffer penalties when trying to take advantage of the less fortunate themselves and commonly suffer guilt penalties when they ignore a chance to help someone out.

Drives have game effects, but their primary purpose is as a roleplaying guide. If you're playing a character's drive properly, you'll hardly ever suffer penalties from it... you won't try to go against the drive, because that's not the sort of thing that your character would do.

You are limited to one primary or "major" drive at a time. Don't worry if you can't think of one right away; you can always pick on later.

Posted by Kiz at 12:04 AM | Comments (0)

Minor Drives

Minor drives work just like your primary drive, they're just weaker. Minor drives only have a game effect when the motivation is particularly strong, and even then the adjustment is +1 if the drive supports the task and -2 if it opposes it.

You can choose up to 3 minor drives for your character. Don't worry if you can't think of any; you can always choose them later.

If you find that you are paying more attention to one of your minor drives instead of your primary drive, you might consider swapping them. Your primary drive should be your character's strongest personal motivation.

Posted by Kiz at 08:58 AM | Comments (0)

April 26, 2004

Buying Skills

There are a number of skills available to characters in Nuclear Beasts. Most of these are quite broad in scope and many will occasionally overlap with other skills. This isn't a problem; when multiple skills apply to a single task, just pool them all together.

The number of skill points that your character receives, and the number of points that can be spent on a single skill, will be determined by your GM.

The suggested values are as follows, depending upon how experienced of characters your GM wants.

  • Beginning characters: 20 points, max 3 per skill
  • Experienced characters: 30 points, max 4 per skill
  • Very Experienced characters: 40 points, max 5 per skill
It costs one skill point to increase your current rating in a skill by one step. For easy reference, the costs are listed below.

You'll generally start with a handful of skills already granted by your chosen breed. If you choose to spend points to improve those, don't count their initial rating when determining how many points you can spend.

d41 point
d62 points
d83 points
d104 points
d125 points
d12,d46 points
d12,d67 points
d12,d88 points
d12,d109 points
2d1210 points
2d12,d411 points
Etc.+1 per die level

Example: If your character starts with a Wilderness skill of d8 from his breed and your GM limited to you spending at most 3 points on a single skill, you could increase your Wilderness rating up to d12 & d4, but no higher. A character who didn't start with the Wilderness skill at all could buy it at up to the d8 level, but no higher.

Optional Rule: Buying New Dice at WillIf you don't mind a little extra complexity, you can allow players to purchase additional dice for a skill even if their current rating is below d12. With this rule, whenever you spend a point on a skill, you can increase any of the dice that are below d12 or add a new d4 to the pool. So, someone who spends 3 points to acquire a new skill could buy it as 3d4 or d6 & d4 or just a single d8.

Posted by Kiz at 07:24 AM | Comments (0)

Skill List

Here is a list of the standard skills in Nuclear Beasts. Each one lists the stat or stats that it is most commonly paired with. A Restricted skill is only available to characters who qualify for it. You should read its description carefully for details.

If you don't see a skill that matches what you want, take a look at the Expertise Skill.

Acrobatics (Speed): Your agility and balance. Acrobatics is used to climb objects and to perform tumbles or rolls as well as general acrobatic manuevers. If your breed can fly, then you'll use Acrobatics to manuever in the air as well.

Ancient Lore (Brains): Your knowledge about the old times, before the Last War. This skill also governs your ability to read and write.

Ancient Tech (Brains): Your knowledge about technology and electronics. Used to try and jury-rig or repair ancient devices. Unfortunately, for many things, the tools necessary to repair them simply don't exist anymore. This is the primary skill of the Engineers.

Awareness (Perception): Your ability to notice things using your regular senses. Most commonly used for Spot checks, Listen checks or Smell checks, but Taste checks are possible too. Note that your ability to detect radiation depends upon your Awareness skill.

Charm (Spirit): Making friends, being socialable, using flattery or seduction, and otherwise ingratiating yourself with others.

Construction (Brains or Perception): Skill at constructing, appraising and dismantling large constructs like buildings, tunnels and bridges.

Contortionist (Speed): Your ability to squeeze yourself through openings that are too small for you and to wriggle out of bonds or wrestling holds.

Craft (Brains): Skill at hand-crafting tools, clothes and other useful items, especially ones that are woven. For large-scale projects like buildings, see Construction.

Endurance (Guts): Your ability to exert yourself for long periods without becoming exhausted; often applies to tasks such as manual labor or cross-country travel.

[Expertise (Any)]: This isn't a true skill as such. Basically, when there aren't any skills appropriate to what you want, you can take an Expertise in a particular area instead. The Expertise should apply to any reasonable task involving that subject. For example, if you took Expertise: Spears, then you could include that skill with Melee when fighting with a spear, with Ranged when throwing one, with Awareness when examining one, and with Craft when making or repairing one.

You can take as many Expertise skills as you want, but they all have to have different areas. It's common for the "Expertise:" to be left off of the skill name when you write it down, so if you see someone with the skill Ancient Vehicles, it's probably shorthand for Expertise: Ancient Vehicles.

Herbalism (Brains or Perception): Knowledge about what plants and fungi do what and how to find them. Often used to find food for herbivores in the wilderness, or to find cures for certain illnesses.

Leadership (Spirit): Skill at leading and inspiring others. Often used to convince others to follow your lead.

Melee (Speed): Skill at hand-to-hand combat, whether with natural weapons or artificial ones. Doesn't apply to actual grappling; see Wrestling instead.

[Psychic Skill (Spirit, Restricted)]: Every time that you take the Psychic Power Edge, you get a new Psychic Skill, named after the Power you chose. If you don't have the Psychic Power Edge, you cannot take any of these skills. See the Psychic Powers section for details.

Ranged (Perception): Skill at ranged combat, including shooting and throwing accurately. Note that ranged combat depends primarily upon your Perception stat, not Speed.

Stealth (Speed): Your ability to move silently and to conceal yourself from observers.

Swimming (Speed): Skill at swimming, diving and holding your breath for long periods.

Thievery (Speed or Perception): Skill at picking pockets, opening locks and general sleight of hand.

Tracking (Perception): Your ability to follow a trail, whether by spotting traces or following scents. Often used to find food for carnivores.

Wilderness (Brains or Perception): Skill at surviving in the wilderness. Covers not getting lost, finding shelter, predicting the weather, and similar tasks.

Wrestling (Muscles or Speed): Skill at grappling and other forms of combat where you attempt to grab and/or pin your opponent.

Posted by Kiz at 07:25 AM | Comments (0)

Task Resolution

When called upon to perform a task, you'll roll a pool of dice. This is generally a single attribute and one or more skills, but it can be two attributes, the same attribute twice, or any other combination.

Task ResolutionThe largest number rolled is your result. Apply any bonuses or penalties, then compare this to the target number you were trying to match or beat. The results can be interpreted as follows:

ResultRoll Required
BotchFail by 4+ or roll the Risk or less unmodified
FailureRoll less than the target number
Partial SuccessRoll the target number or higher
SuccessBeat the target number by 4+
Critical SuccessBeat the target number by 8+
Extraordinary SuccessBeat the target number by 12+

If the rules don't say what difficulty to roll against, you can assume that the target number is 4. That's the standard difficulty for tasks in Nuclear Beasts. Thus, we have the Standard Task Resolution table below.

Standard Task ResolutionIf the rules don't specify a particular difficulty, just roll against difficulty 4. Apply any bonuses or penalties, then check the table below for the results:

ResultRoll Required
BotchRisk or less unmodified, or less than 1 after modifiers
Partial Success4-7
Critical Success12-15
Extraordinary Success16+

Technically, if you beat the target number by 16+ (a 20 on a standard test), it's an Extra2 and beating it by 20+ (a 24 on a standard test) is an Extra3, but these won't come up much in play. The GM is encouraged to think up appropriate effects for such phenomenally high rolls.

Posted by Kiz at 07:33 AM | Comments (0)


When you look at the basic resolution tables, you'll see that failing a roll by 4+ or rolling the Risk or less is a Botch.

Failing by a lot is fairly intuitive, but what is the Risk of an action?

The Risk is the number that you have to beat with your unmodified die roll to avoid a Botch. That's important; bonuses and penalties don't apply to figuring out whether or not you beat the Risk- we only care about the actual numbers rolled.

The default Risk for any action is 1. Thus, you'll only roll a Botch if every die rolled comes up a 1. If the Risk for an action was 4, you'd suffer a mishap if the highest die roll was 4 or less. Obviously, the greater the Risk, the more dangerous it is to attempt the action.

A Risk of zero is harmless. No die can roll that low without modifiers, so you don't need to worry about it.

A Risk of 1 is pretty mild. If you're rolling even two dice, you're pretty well protected against a Botch. With three or four dice, getting all ones is really rare (it happens on 3d4 only one time in sixty-four). This is the default Risk for any action.

A Risk of 2 is a good bit more dangerous. For example, if you were rolling 3d4, the odds of scoring a mishap would go up to one in eight instead of one in sixty-four. That's an eight-fold increase.

And if the Risk gets up to 3 or 4, well... you'd better be prepared for a Botch unless you're rolling a lot of very large dice. Even if you were rolling 3d8, with a risk of 4 you'd score a mishap one time in eight. Worse, a 4 would no longer be a success when making a standard test... it would be a Botch. Try to avoid tasks with Risk ratings that high.

When you roll a Botch, it means that something went very wrong. Perhaps you accidentally shot an ally or said exactly the wrong thing. If the task in question doesn't specify what form a Botch should take, the GM should invent some sort of goof-up or complication that seems appropriate.

Posted by Kiz at 07:35 AM | Comments (0)

Opposed Tests

If something that you're doing is being opposed by someone else, you'll generally roll your pool of dice versus whatever pool of dice they're using to oppose you. Thus, the target number will vary depending upon how good they are at what they're doing and how well they roll.

Sometimes it's possible for either side to "win" the struggle. In this case, both sides roll and you treat whoever rolled higher as though they were the one performing the action. If the two rolls are identical, this is a Tie. This usually means that there's no clear winner; for the moment, it's a stalemate.

Posted by Kiz at 08:44 AM | Comments (0)

Target Numbers for Unopposed Tests

When you're performing a task that doesn't involve direct opposition by someone else, the target number you need to succeed will be determined by how difficult the task in question is. For predictable tasks, where random chance shouldn't play a large part, the difficulty should be a set value. On the other hand, if you want the task to always be beatable by anyone (but not necessarily easily), then you should set the difficulty to a random amount.

DescriptionSet DifficultyRandom Equivalent
Very Easy2d4 (ave 2.5)
32d4 (ave 3.13)
Typical42d6 (ave 4.47)
5d8,d6 (ave 5.23)
62d8 (ave 5.81)
72d10 (ave 7.15)
Hard82d12 (ave 8.49)
93d12 (ave 9.48)
104d12 (ave 10.07)
114d12+1 (ave 11.07)
Very Hard124d12+2 (ave 12.07)
Nigh Impossible13+4d12+3 and up

Posted by Kiz at 11:54 AM | Comments (0)