This thread describes the basic rules of the game, as taken from the core rulebook (the Rules section starts at page 104, though it's bookmarked anyway in the PDF). I'm roughly paraphrasing what it says there, so if you want the more detailed version, you can just read through it in the book. I'll go through each section of that chapter in order, with the same subheadings, for ease of reference.
Dice
This game's dice system is binary, so it doesn't matter what kind of dice you use, as long as they have an even number of sides. The default is set for 1d2, so you would just change that number to reflect your die pool. For example if your die pool is 5d, you would set the dice roller for 5d2...
When making rolls, you roll the appropriate number of dice and count up how many even numbers you rolled - this is the number of successes and when compared to the difficulty of the roll, will tell you how much you passed/failed by. The number of dice you need to roll is called your dice pool.
Please post your rolls at the bottom of your IC posts, when appropriate.
Rules Overview
Whenever you want to take an action, there are seven steps to follow...
~Declare action
Describe the action your character is taking, its type, then determine the appropriate skill/stat roll and its type.
~Determine difficulty
The GM determines the difficulty of the roll, based on the action being taken and the stats/skills being used.
~Calculate dice pool
Work out how many dice you need to roll by looking at the appropriate stat/skill rating and applying any modifiers.
~Take the average
If the average of your dice pool is already enough to beat the difficulty, you automatically succeed without needing to roll and can skip the next step.
~Roll dice
Roll however many dice need rolling, and count up your successes (even numbers).
~Resolve action
See whether or not you succeeded at the action, based on the number of successes you rolled compared to the difficulty of the task.
~Try again (optional)
Depending on the action, you may choose to attempt to try again (with the GM's approval). In this case, go back to the "roll dice" step but with a -2 penalty.
Time
As with any RPG, time can flow differently depending on what's going on - a few seconds of game time can take a long time to get through, but a journey of several days might be skimmed over in a few moments (assuming nothing of note happens during said journey). Time in Hollow Earth Expedition can be broken down into the following "categories", from shortest to longest...
~Combat turn
Lasts six seconds - enough time for a character to perform (usually) a single action.
~Scene
Probably the commonest "unit" of time in the game, a scene could probably compared to such in a film or play - once the action moves on to another location or a new event takes place, that scene is over and a new one begins. As such, scenes have varying durations.
~Game session
Not so relevant here as this is a forum-based game, this would normally be exactly what it sounds like - a single game session lasting from the time everyone sits down to play the game, until the time they pack up and leave, hopefully having achieved something significant during the session. The end of a session is when exp is supposed to be given out, but as this game doesn't have sessions, obviously that will be handled differently.
~Story
As it sounds, a story is one complete...well, story. Basically it's the duration of a single plot line, at the end of which the game can finish up permanently, or perhaps the characters might be carried over into a new one.
~Downtime
In a normal, tabletop game, this is usually the point between sessions where characters are having a rest and generally not doing much of note. This is when experience is usually spent (characters are considered to be working on their skills and stuff, which explains why they're better at the start of the next session).
~Campaign
Multiple stories connected together to form an overarching plotline or similar.
Actions
There are four different types of actions characters can perform, depending on the time taken and some other modifiers...
~Standard
Pretty straightforward, a standard action is something relatively simple which can be resolved by a single roll of the dice. If you roll enough successes, you pass. If you don't, you fail.
~Extended
These are actions which require more than one roll in order to resolve them, so are generally things that will take some time to complete (such as repairing a building or vehicle, or copying out a large amount of text or a map). For these actions, you'll need to make multiple rolls, with each roll representing an amount of time (for example, one hour), during which you're worked at the task. The difficulty of these actions will be subtracted from the number of total successes you need to roll.
For example, suppose you need eight successes to pass at your attempted action, which has a difficulty rating of two. You roll the appropriate skill and get three successes. You then subtract the difficulty from your successes (so in this example, subtract the difficulty of two from your three successes), giving you a total of one success. So now you need seven more, and thaat one roll represented, say, half an hour of work. So you roll again, and this time roll five successes, subtracting two for the difficulty which makes three. Adding this to the success from before you've now scored four so after an hour of work, you're halfway there. You keep going until you either succeed or give up.
~Opposed
These are actions that involve more than one person acting against each other (for example, trying to outrun someone to a goal, or whack them round the head with someone). In this case, you'd both make the appropriate skill/stat roll and the one with the most successes wins. If both characters roll the same number of successes, the result is a tie, with neither character getting the upper hand - if one character is defending against another (eg trying not to get punched in the face), a tie means the blow lands but wasn't good enough to actually do any harm. If two characters are racing for the same goal, the one who rolls enough successes first is the one who gets there first - if both achieve this at the same time, then of course, they both arrive at the goal simultaneously.
~Reflexive
These are usually actions performed in response to something else - they aren't considered to take any time and don't tend to incur penalties because they're performed as a result of something happening to your character. Trying to dodge a punch or grab something as you fall would be considered reflexive actions.
Difficulty
This is determined by the GM and is based on the nature of the action being taken. You need to roll enough successes to beat the difficulty rating, which will usually vary between one and five, though six or higher is possible. Each level of difficulty can be described as follows...
1 = Easy
2 = Average
3 = Tough
4 = Hard
5 = Very Hard
6+ = Nigh Impossible
Dice Pool
Your dice pool is the total number of dice you roll when attempting an action. Due to the fact that every action will have different circumstances, the dice pool will vary between rolls since everyone's skills and stats are different, as will be the situations in which various actions are likely to be attempted. When making a roll, you should...
~Look at which skill will be the most appropriate for that particular action (if any).
~If you possess that skill, your dice pool will be equal to that skill's rating (plus any bonus dice for skill synergy, if applicable - see below).
~If you don't possess that skill, your dice pool is equal to that skill's governing stat -2 (for example, if you need to fire a gun but don't have the Firearms skill, you'd roll your Dex stat -2 dice. So if your Dex stat was 3, you'd roll one die).
~If you both possess the skill and have any points in an appropriate specialization (for example, you're trying to fire a pistol and have both the Firearms skill and a specialization of Pistols), you get to add bonus dice to your pool equal to the number of points you have in the specialization (ie one point in Pistols gives you one extra die when firing one).
~Note that Specialized Skills (Science, Pilot, etc) cannot be attempted if you have no training in them. If you have training in one discipline of that skill (for example if you have Science: Biology), you can attempt to test another, untrained discipline of that skill (eg Science: Physics), but at a -2 penalty.
~If there is no applicable skill for the roll you're making, you roll either the appropriate primary stat x2 (Int, Str, etc), or the appropriate secondary stat (Move, Initiative, etc).
Having done this, you'll have your base dice pool for the roll. So next, you need to take into consideration...
Modifiers
Various things will affect the likelihood of your passing a roll. You might be pushed for time, or have to make do with makeshift tools. Alternatively, you might have the aid of a skilled assistant, or perfect weather conditions. This kind of stuff adds modifiers to your roll, which means you get bonuses or penalties, adding or removing dice from your pool. You can't have more than ten dice added to or subtracted from your pool. If modifiers cause your dice pool to drop to (or below) zero, you automatically fail at the task without the need to roll.
Your dice pool can be modified by the following things...
~Equipment
Having the right equipment for a job can give you bonuses to your roll. This also goes for weapons in combat. Conversely, of course, having the wrong kind of equipment (or just crappy/broken equipment/weapons) will impose penalties. Note that bonus/penalty dice from equipment don't count toward the ten-dice maximum for other modifiers.
~Circumstances
It might be dark. Your character might be injured. Maybe it's completely pissing it down and you're stumbling about on the slippery ground in low visibility. Or maybe it's nice and sunny and you can see perfectly. Maybe that weird fruit you ate earlier is making you feel more energetic than usual. All this kind of stuff can affect your dice pool, and you'll be informed by the GM as to whether or not it does at the time.
~Time
As you might expect, taking your time over something will hopefully mean you're less likely to make mistakes, and therefore even though it takes longer, you'll get the job done better. And of course, if you're rushing the job super-fast because you really need it done right now, you can expect things to not necessarily go quite the way you'd want. Working at a task at a faster or slower rate than normal will affect your dice pool.
~Skill synergy
If you have more than one skill that could be used for a task, you get to add bonus dice for it. You use the rating of the highest applicable skill for the roll, but any other applicable skills with a rating of four or more will give you +2 dice to your pool (to a maximum of ten bonus dice). So say you want to ride a nervous horse, and you have both the Ride skill at six, and the Animal Handling skill at four. Both skills could be applicable. You'd use your Ride skill for the roll (six dice), but would get a bonus two dice because your Animal Handling skill is at four. So you'd have a base pool of eight dice (before applying any other modifiers).
~Teamwork
This is similar to skill synergy, but applies when multiple characters have suitable skills. In this case, the person with the highest applicable skill rating would be the one making the roll, but anyone else with a rating of four or higher in an applicable skill gives that person a +2 bonus. As usual, you can't get more than ten bonus dice from this.
Taking the Average
Due to the binary nature of the dice system, you can work out the average number of successes you're likely to get at any given roll, just by dividing the number of dice by two. This will give you the average number of successes you're likely to get if you were to make that roll a load of times. Therefore, if your average roll is higher than that of the difficulty of the task, you're considered to have automatically succeeded without the need to roll. So for example, if you have a Biology skill of six and need to identify that big dinosaur that's coming toward you, but it's a relatively well-known one so only has a difficulty of two, your average (half your skill) is three, which beats the difficulty, therefore you don't need to roll any dice to recognize that it's a brachiosaur so at least you don't have to worry about it trying to eat you.
~Taking the average of odd numbers
When working out the average score of an odd number, you halve it and round down, putting a "+" after the number. For example, if your Firearms skill is five, half of five is 2.5 but instead of writing that, you write "2+". This represents that on average, you're likely to roll between two and three successes, but obviously you can't roll half a die so this is how it's represented. When you need to Take the Average of this dice pool, you roll one die. If it comes up a success, use the higher number. If not, the lower. In the above example, a success would mean you count your Firearms skill as three for that particular skill test, while a fail would mean it counts as two. You compare this number to the difficulty of the task and, as above, if it meets or beats it, you succeed.
~Modifiers and Taking the Average
Situational modifiers affect your average just like they do a normal roll, raising or lowering the score without your necessarily needing to roll any dice. If your average is three, a bonus dice would increase that to 3+. A second would increase it to four, and so on. And the same in the other direction. If the modified average is a number with a "+" after it, you'll need to roll a single die to see if that "+" is worth an extra point or not. If the final average is enough to meet or beat the difficulty, then you succeed without needing to make the actual roll.
Resolving Actions
Basically, any action which might succeed or fail will require a test to see which outcome occurs. Ordinary, everyday actions which your character shouldn't need to put any effort into can probably auto-succeed...unless you're under pressing circumstances or there's some other reason why you might not succeed at it this time. Also, how well did you succeed? Did you only just manage it, or was it a spectacular success? Did you only miss it by a tiny amount, or did you just faceplant from two metres up?
~Rolling dice
Put simply, the more you beat the difficulty by, the greater the level of success. And conversely, if you fail by a lot, you're probably going to be worse off than if you only failed by a point or two.
~(Optional) Rolling large dice pools
If you have to roll a large dice pool (more than ten dice), you can choose to Take the Average of the first ten dice (so, five) and then roll the rest, adding those successes to the average score taken from the ten.
~Degrees of success
This is where you compare the number of successes you rolled to the difficulty of the roll in order to see what level of results you're gonna get. Each point by which you pass (or fail) is one degree of success (or failure).
Successes vs. Difficulty Degrees of Success/Failure
+5 or more Amazing success
+4 Exceptional success
+3 Major success
+2 Complete success
+1 Simple success
0 Minor success
-1 Simple failure
-2 Complete failure
-3 Pitiful failure
-4 Dreadful failure
-5 Abysmal failure
The effects of these degrees of success are usually roleplayed - if you were trying to get some information out of someone and passed by a lot, you'll probably get everything you wanted to know plus some stuff you didn't. If you passed by just a bit, you might get a few useful facts but not necessarily every tiniest detail. If you failed by a bit, they might just refuse to tell you anything. If you messed up pretty badly, they might even attack you.
This also comes up during combat, where beating someone's Defense score by a lot means that you got through their armour/block/attempted dodge and hit them pretty hard. If you failed to beat their score, you missed or your attack was only a glancing blow that didn't really affect them too much.
~Critical failure
If, on making a roll, you roll no successes, you have critically failed. As such, something bad is going to happen, however it will be less bad if the task you were attempting had a lower level of risk. For example, botching at picking a lock at night with nobody about will probably just mean that you broke your pick off in the lock - okay so you've lost your pick and someone's probably gonna find it in the morning, but you're not in immediate danger or injury or death or anything like that. On the other hand, botching at trying to leap across a deep crevasse with crumbly edges while a smilodon rushes at you from behind is likely to be...less than pretty.
Trying Again
If you fail at a task, you may (depending on the circumstances and with GM approval) be allowed to try again. This means you can make the same roll, but at a -2 penalty. Not all actions can be tried again - attacking someone in combat, for example - if you try to hit them round the head and miss, circumstances will have changed by the time you consider trying again because chances are the other person will now be trying to hit you. You also can't try again at extended actions, because each roll is considered part of the same action. Generally, trying again will apply to actions where you have the time to...well, try again, without worrying about any immediate interruptions or circumstances for failure (for example, trying to climb a wall or unjam a weapon outside of combat).
Style Points
These are those things you get for doing cool stuff in-game. They can be used to modify dice pools, affect the results of actions, assist other players, and a few other things.
~Earning Style points
The GM decides when you get a Style point. Generally you'll get them for stuff like roleplaying something really cool, or generally doing stuff that benefits the game as a whole. You can also get Style points for the following reasons...
Acting on your character's Motivation
Acting out your character's Flaw(s)
In-character roleplaying and stuff
(There are a couple of other things, but they mainly apply to tabletop games, which this isn't, so they're not really likely to come up ;)).
There's no limit to the number of Style points you can earn, but the GM might limit you to earning a certain number within a certain amount of time.
~Spending Style points
You can use Style points for a variety of reasons. Note that once spent, a Style point is gone and you must remove it from your total. You don't regain spent Style points - you get awarded new ones by the GM.
You can use them to buy bonus dice, good for a single roll. You get one bonus die per Style point spent, to a maximum of ten bonus dice. You can also use Style points to boost the average of a roll in the same manner.
You can use them to boost Talents. A Talent is boosted by one level for every two Style points you spend on it. This improvement lasts for an entire combat, or until the end of the current scene (if outside of combat), at which point it reverts to its previous level. You can't boost unique talents (since they only have one effect which can't be improved upon), and you can't boost a Talent you don't have. You also can't improve a Talent beyond its maximum level.
You can use them for damage reduction, spending two Style points to reduce damage taken by one. This only works immediately as you get hit (and is considered a reflexive action), but the GM may allow you to spend them later, after the combat, to represent your character healing faster, for example, or the wound not turning out to be quite so serious as it first looked. Spending Style points on damage reduction during combat can be useful for non-combat characters whose health is naturally low.
You may also be permitted to spend Style points to affect other things, such as causing the effects of an event to turn more in your favour, or something.
~Sharing Style points
You can't give away or trade Style points. However, you can spend them on behalf of someone else. You'll need to RP exactly what it is you're doing - for example, spending your Style points to boost someone else's Defense rating as they're about to be hit, RP'd by having your character yell at them to get out of the way, or give them a shove.
Chance Dice
If you've run out of Style points (or even if you haven't), there's still a way for you to get bonus dice. However, it's a bit more risky. You can ask the GM for any number of chance dice. These are bonus dice which are added to your dice pool, but for every two chance dice you get, the difficulty of the roll is increased by one. As usual, the maximum number of dice you can get in this way is ten, which would mean an extra +5 to the difficulty.
If you take any chance dice, you can't then Take the Average.
You can spend Style points and ask for chance dice for the same roll. You still can't get more than ten bonus dice in total, though.
Experience Points
As your characters grow over time, their skills and stuff will become better. This is represented by the acquisition of experience points, which can be spent on various improvements to your character.
Normally, experience is given out at the end of a session, but for the purposes of this game, they'll be given out when you reach a "safe spot", somewhere you can relax for a bit, even if not enough to have any proper downtime in order to spend it. So pretend that this game is broken up into "chapters", or something, rather than sessions.
You get experience for the following...
Automatic - You get a point just for taking part in the game.
Danger - You get a point whenever your character survives some kind of dangerous encounter.
Roleplaying - I'd hope that everyone will be RPing, seeing how this is a forum-based game, so I might modify this one to be "whenever you do something really cool that probably earned you a Style point at the time as well".
Success - You get a point for progressing through a plot point or otherwise taking a step closer to whatever your current goal is.
Wisdom - You get a point whenever your characters learn something really important.
Other - You may also get experience for other stuff, like reaching the end of the current "story" or whatever.
Spending Experience Points
You can spend your exp on Stats, Skills, and Talents. You may be permitted to spend them on Resources, but you'd need to come up with a good enough reason for it. Resources tend more to be gained or lost during play, rather than outright bought for experience.
When spending your exp, you'll need to justify it - you can't have your character suddenly knowing Karate if there's no-one around to teach it! If your choice of exp expenditure doesn't seem to make sense, you may be asked to explain it.
The following table depicts the exp costs of stuff...
Trait Exp Cost
Primary stat New level x5
Skill New level x2
Skill Specialization 3
Talent 15
Resource 15
Note that you can't raise any single trait by more than one point at a time. This is to represent the fact that this stuff takes time and effort to improve.
That's about it for the basic rules. I tried to keep it as simple as possible, but didn't really need to paraphrase too much from what's in the book, considering the book lays it out quite straightforwardly anyway.
