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Game Rules

The Game Master, also known as the GM, will be responsible for running the Atomic Role Play Game. The Atomic RPG System has been simplified for quick and easy game play. Here are some Atomic RPG System game rules to help make decisions on what a character can do or if they will be successful.

Since the Atomic RPG System System is so open and inviting to an almost infinite amount of play styles and games, it will be impossible to cover every situation. However, these additional rules may help keep your Atomic RPG System game running smoothly. If questions remain about how to work through a certain situation or setting, please feel free to post in the Atomic RPG System Forums.

Most of the Atomic RPG System game rules will be explained in other specific sections. However, situations that don’t quite fit or are GM-specific and not player character-specific may be mentioned here.

Bonuses and Penalties – A GM’s Best Friend

There are many times during a Atomic RPG System game where the GM needs to assign an additional bonus or penalty to a situational roll. The Atomic RPG System makes this process very fast and easy for the GM. GMs in the Atomic RPG System simply say if the temporary GM bonus or penalty is minor or major.

This will be a one-time modification to whatever the player is rolling, given to players occasionally when the GM thinks they deserve an extra bonus or penalty to whatever they are attempting. Simply assign them their Character Tier as a modifier if it is minor. If the modifier a GM wants to apply is a major one, then assign it as twice what their Character Tier is.

This method is used in Skill Checks, but it can also be applied to some situations as an Attack Bonus, or Defense Penalty, or affect whatever the GM feels is appropriate at the time. This way the GM and the player do not need to agonize over what a modifier is or should be. It is simply a minor or major modifier.

This is considered a GM Modifier specifically, so it will stack with everything.

Character Bonuses, Penalties and Stacking

When calculating all character statistics and numbers there is one important rule to remember: no character bonuses of the same type stack. The lone exception to this rule is a GM bonus to anything. The GM always has the ability to grant bonuses (or penalties) that will stack with everything else a character may have. Character Bonuses and Character Penalties are treated as separate types.Characters will always use the greater bonus when deciding between bonuses of the same named type. If a character currently has multiple bonuses of the same type and for some reason the character loses the greater bonus, the lesser bonus will immediately take effect. In other words, player characters can have many effects of the same type active but only one gives them a bonus at a time.

Here is a list of the base bonus types used in the Atomic RPG System system:

  • Base Score: The score your character starts with is not a bonus.
  • Specialty Bonus: A bonus from a Specialty.
  • Item Bonus: A bonus granted by wearing an item.
  • Item Penalty: A penalty imposed by wearing an item.
  • Power Bonus: A bonus from being effected by a Power.
  • Power Penalty:  A penalty from an enemy’s Power.
  • Combat Bonus: Any bonus gained from your combat prowess such as when flanking.
  • Environmental Bonus:  A bonus OR penalty due to the environmental conditions (such as a blizzard).
  • GM Bonus: Any bonus granted by the Game Master.
  • GM Penalty: Any penalty imposed by the Game Master.

Knowing the way these bonuses and penalties work together will speed up the Atomic RPG System game. Most of these are automatically calculated on the Character Sheet. The few that are not are situationally based which are easily added into the rolls for the situation.

Environmental Effects

Environmental Effects are a very easy game rule that GM’s can use in many situations. They can be used when a there is a mild storm. They can also be used when players are out of their element, such as stuck out at sea. Environmental Effects also come into play when the players are in a deadly environment, such as being sucked out of an airlock into space! Instead of having volumes of books like Dungeons & Dragons to pile on more rules for a specific situation, the Atomic RPG System uses Environmental Effects that cover it all. This makes it much easier to implement, manage, and create the wacky situations players may find themselves in.

There are three distinct levels of Environmental Effects to use in the Atomic RPG System. Here they are and the game rules that will need to be applied to each.

Minor Environmental Effect

This will be used most of the time as the default Environmental Effect to use as a game rule when the players are having a harder time than normal in the environment. Minor Environmental Effect is the perfect game rule to apply to situations such as being in a storm, during dusk or a moonlit night, or even when the person is sick. It represents some challenges to the character while working in a particular environment, but nothing that can’t be overcome with some determination.

  • Character Tier Penalty to d20 Rolls. Players will receive a penalty to d20 rolls equivalent to their Character Tier. This affects Attack Rolls, Skill Checks, and Combat Maneuvers.

Major Environmental Effect

This is used when the players find themselves in a place or situation that is completely foreign to them.  Major Environmental Effect is a good game rule to apply to situations suchs as doing things in a pitch black night, or stuck afloat at sea, or even when they are bedridden with a nasty case of the plague. This represents the difficult challenges to the player in working in an very foreign situation.

  • Character Tier x 2 Penalty to d20 Rolls. Players will receive a penalty to d20 rolls equivalent to their Character Tier times two. This affects Attack Rolls, Skill Checks, and Combat Maneuvers.
  • Character Speed is reduced by 2.

Deadly Environmental Effect

Deadly Environmental Effect will occur when the players find themselves in a deadly place or situation. It is a great game rule to apply to situations such as in space without a spacesuit, falling into lava in a volcano, or stuck in the deep ocean unprotected. This should only be used in rare situations.

  • Character Tier x 5 Penalty to d20 Rolls. Players will receive a penalty to d20 rolls equivalent to their Character Tier times five. This affects Attack Rolls, Skill Checks, and Combat Maneuvers.
  • Character Speed is reduced by Character Tier.
  • The character will take 25% of their total maximum Hit Points every round they are exposed to the Deadly Environment.

If the Deadly Environmental Effect seems extreme, it is! It should only be used in rare situations. If players willingly want to enter a deadly environment, they need to be aware of the Deadly Environmental Effects. The amount of damage continues to increase past 100% because Recovery, Resistance, Powers, and other things may come into play. Smart groups of players will work together to grant bonuses and heal players that enter areas with Deadly Environment Effects.

Here is an Environmental Effects chart to help classify a situation. This is not a hard and fast rule, just a tool a GM can use to set the Environmental Effects. This is designed so that “Normal” is average human conditions. For each of these 4 basic areas that are off “normal”, one step of Environmental Effects can be added. Note, these steps should be considered extremes. So “Hot” is not just a warm day, but a record-setting day. Scorching is literally scorching: easily flammable items can and will spontaneously combust. Dark is not a dark starry night–it is absolute darkness.

Environmental Effects Reference Table
Light Dark Dim Normal Bright Brilliant
Temperature Frigid Cold Normal Hot Scorching
Area Solid Liquid Normal Gaseous Vacuum
Water Soaked Wet Normal Dry Barron

When comparing Environmental Effects between PCs and NPCs, take into account the “Normal” for the NPC. For example, if the player characters are in the arctic and encounter a polar bear, the player characters will consider the temperature is cold, but everything else is Normal, so they will be dealing with a Minor Environmental Effect. For the polar bear NPC, everything is Normal, so it will not suffer any Environmental Effects.

Underwater Environmental Effects

One of the most common Environmental Effects the party is likely to encounter is water. Just swimming on water is fine, but what happens when the character is submerged underwater? The solution is easy. The player will have Minor Environmental Effects while it can hold it’s breath. As soon as it can’t the character starts to drown. At that time the player will be affected by Deadly Environmental Effects because they are dying! See the Athletics Skill or Nature Skill to see how long players can hold their breath.

Movement Modifiers and Difficult Terrain

Movement Modifiers are used by the GM to make certain terrain or areas difficult to move through. These give the GM the ability to modify the battlefield in interesting and challenging ways. This can greatly enhance combat and strategic battle.

  • Minor Movement Modifier – Each Space counts as 2 Spaces for movement. Examples might include terrain like a few inches of mud, ice, or spider webs.
  • Major Movement Modifier – Each Space counts as 3 Spaces for movement. Examples might include terrain like a few feet of mud, deep powdery snow, or thick mangrove jungle.

Battle Surprise – Spice up Battle Time

Below is a table used to add Battle Surprises. These are unexpected things that can happen during Battle Time that can make combat much more exciting. This should be rolled in secret by the GM on the 2nd or 3rd round if the GM decides they want to use a random Battle Surprise. However, it may fit the story better for the GM to look at the below list of ideas and manually add them to appropriate encounters. This way they may fit a little better into the story of the quest.

Read more about Battle Surprises on this blog post: Battle Surprise Blog Post for Battle Time

Random Battle Surprise Table

d20 Description Effect
1 A terrible storm or other weather like phenomenon occurs. If indoors there is a sudden gas leak, pipeline break, or power outage. Superior Environmental Effect
2 Damage Hazard – Fire pit, acid pool, or other damaging area is discovered or appears. d20 x Character Tier Hit Point Damage
3 Movement Obstacle – A tree falls, a pit is discovered, or security doors drop to change the battlefield. 25 Spaces – DC 40 Bypass
4 Movement Hazard – Area on battlefield becomes difficult to move in or through. Oil, blood, rubble or debris restrict movement. 6×6 Area – Spaces Count as 3 when moving.
5 Reinforcements Arrive A few more of the weakest NPCs arrive to bolster the ranks.
6 Movement Hazard – Area on battlefield becomes difficult to move in or through. Oil, blood, rubble or debris restrict movement. 5×5 Area – Spaces Count as 2 when moving.
7 A storm or other weather like phenomenon occurs. Minor Environmental Effect
8 Movement Hazard – Area on battlefield becomes difficult to move in or through. Oil, blood, rubble or debris restrict movement. 4×4 Area – Spaces Count as 2 when moving.
9 Movement Obstacle – A tree falls, a pit is discovered, or security doors drop to change the battlefield. 16 Spaces Area – DC 30 Bypass
10 Damage Hazard – Fire pit, acid pool, or other damaging area is discovered or appears. d10 x Character Tier Hit Point Damage
11 Movement Hazard – Area on battlefield becomes difficult to move in or through. Oil, blood, rubble or debris restrict movement. 3×3 Area – Spaces Count as 2 when moving.
12 Movement Obstacle – A tree falls, a pit is discovered, or security doors drop to change the battlefield. 9 Spaces Area – DC 20 Bypass
13 Damage Hazard – Fire pit, acid pool, or other damaging area is discovered or appears. d6 x Character Tier Hit Point Damage
14 No Battle Surprise – Just go about the Battle Time Encounter as normal.
15 No Battle Surprise – Just go about the Battle Time Encounter as normal.
16 No Battle Surprise – Just go about the Battle Time Encounter as normal.
17 No Battle Surprise – Just go about the Battle Time Encounter as normal.
18 No Battle Surprise – Just go about the Battle Time Encounter as normal.
19 Enemies flee or surrender. Enemies surrender or flee at 25% Hit Points.
20 Enemies try to kill other enemies to gain station or repay a grudge. They include them in attacks or at the least fail to help them in the most advantageous way. Enemies attack enemies.

Availability of Items to Characters

Here is a quick reference table Atomic RPG System players can use to get a general idea if an item is available. Remember, it is always ultimately up to the GM, this is just a guideline.

Availability Description Cost Roll
Common Common items that just about anyone has. Common items are easy to find. 4,000 5 or Higher
Uncommon This is an uncommon item which may be expensive or hard to come by. 10,000 10 or Higher
Rare This item may be available but expensive and hard to come by. 26,000 15 or Higher
Very Rare This item is rarely available for purchase. Usually a substantial sum of cash is needed as well as some kind of service. 68,000 18 or Higher
Unheard Of This item is never available for purchase. If someone is lucky enough to have such a powerful item they never give it up voluntarily. 178,000 20
  • Availability – The name used to describe how available the item is.
  • Description – A quick description on the item’s availability.
  • Cost – The base cost of this level of availability. No matter what the item is, its value will determine its availability.
  • Roll – The roll that would be needed if the player is allowed make a roll to see if the item is available for purchase or trade. Rolls are made with a d20 (20 Sided Die). The player can add their Character Tier to the roll.

These are the Atomic RPG System Game rules that do not fit well in other sections of the Atomic RPG System website. Most rules for the Atomic RPG System are explained in full in the specific section of the Atomic RPG System website. Use the search feature on the Atomic RPG System website to find the game rules you are looking for. For further discussion and clarification on specific Atomic RPG System game rules, look on our Atomic RPG System Forum or Atomic RPG System FAQ page.