Group Actions

+ + Group Actions + + It's often interesting to see the characters cooperate + together for a particularly difficult task, or to put at the head + of a troup of kobolds and see how they can make them efficient. The problem meet most often + here is that the rules that they know can only be used to rule for + one character at once, asking for rolling dice for each character + and each action, which is quite long. Arpeggii uses some + shortcuts to manage those kinds of ruling, with only one roll, and + obtains similar results as if each character have roll for + themself. You can them compute the + total power of a group, count + the number of success in a group with only one roll, and + even determine the degrees of + success of each individual character of the group. + +

+ Values Combination + + Some actions can be sometime impossible for one individual + and required the cooperation of the group to be succeed. + However, attach a young puppy to a group of 10 horses will not + help a lot to the task. To find the strength of the group, you + can combine the characters' Attributes. + The simple method is to convert all of them in Measures, add + them and convert it back in Value. This way can became long and + tedious however when they are many characters. + + Another way is possible but required a bit of practice from + the GM to be efficient, and can be long if the group is too much + heterogenous. However, as soon as the group is composed of + individual with identical attributes, the calculation became + very quick and make it very clear when someone will not add + something interesting to the total strenght of the group. + + + Calculation of Values Combination + + Take each individual with the same Value and form a + group. The Value of those group will be equal to the common + Value of each individual, plus the Value corresponding to + the number of individuals in the group (e.g. +5 is you have + 3 individuals, or +0 if you only have one). + + + Take all groups with the same Value and combine them + again but this time by adding the Value of the number of + groups instead of the number of individuals. For example, + if you have 3 groups with +2 each, whatever the number of + individuals in those groups, the new group will have a Value + of +2 + 5 (the Value of 3), which is +7. + + + Take the two groups with the least Value. + + + If the difference between both is 3 points or less, + combine them in a new group with give them the Value of + the strongest one +2. + + + If the difference is between 4 and 6 included, + combine them and give the Value of the strongest +1. + + + If the difference is greater than 6 points, discard + the weakest group and keep the stronger. The weakest + group will be ignored in the total but if a new + individual is add at later time, you'll be able to check + if he can be add to discard groups first to form a + strongest group. + + + + + Redo the last two steps until you have only one group + left, except for the discard groups. The combined Value of + all individuals will be the Value of this final + group. + + + + It should be note that's not always possible (or realistic + if you prefer) to combine Value this way, and the Game Master + can always impose some penalities and even restrictions to the + numbers of characters which can participate and for their + know-how, including asking for a leadership roll to the chief of + the group. It's the GM responsability to create the right + suspension of disbelief and keep the players interest. + + + Group Value Combination + + A group is composed of 6 characters with a score in Body + of -10, -5, -5, +3, +4 and +5. Since they are already + ordered, we can began to group them: + + + + First, we group the identical Values: We have two + individuals with -5. We can so group them by adding to + them the Value of 2, which is +3. The new group value + will be -5 + 3 = -2. + + + The two weakest groups can are now -10 and -2. The + difference is 8 points, so the -10 group (a single + individual) can be ignored. + + + We now compare the -2 and +3 group. The difference is + 5 points and so we combine both groups and give them the + value of the stronger (+3) augment of one point, for a + total of +4. + + + In the remaining groups, we now have a new identical + pair, which is two +4 groups. Again, we can combine them + in a new group by adding +3 to the common Value, for a + total of +7. The group is now composed of 3 subgroups, + one ignored (-10), a +5 and a +7 group. + + + We compare again the two weakest, +5 and +7 (the -10 + is still ignored). The difference is only 2 points. The + groups can so be combined in a new group with the highest + Value (+7) augment of 2 points, for a final group with a + combined Body Attribute of +9. + + + + Remark that if the group at -10 was compared with the -5 + group first, you will got a group with -4, which combined with + the other group at -5, will also give you a group with -2. + So, it doesn't make any difference at the end and since the + combination of identical groups is the only one which can be + done on multiple groups at the same time, she is favored most + of the time. + +

+ +

+ Rolling dice for a group + + In a game, the players are often confronted to group of NPC + sometime numerous and often hostile. In a combat or a pursuit, + it will be tedious for the GM to roll dice individually for each + members of the group. When the group is sufficiently homogeneous (no more then 5 points of + difference in their Competency Level for this particular action) + et that the roll is a simple + action, a quick alternative can be used instead. First, + the Game Master make a normal roll for the whole group. Then, + she takes the Value of the total number of members in this + group. To this value, she subtracts either the degrees of + success if this one is positive or the degrees of failure + elsewhere, and then subtracts 3 more points to the result. The + result will always be at most the Value of the group minus 3. + This Value can then be converted in a Measure and round up to + the lower whole number. If the roll was positive, this Measure + represent the number of individuals that + failed their roll. Elsewhere, it represent + the number of individual that succeed their roll. + + + Simple Group Roll + + A group of 25 guards try to catch the characters in a + mountain road. The characters decide to destroy a little + bridge to slow them down. The guards decide to jump over the + small gap. The difficulty is -5 under Ag+Pw, where the guards + have a total of +3 each. The Game Master roll the dice and + get +4, which is a +2 degrees of success. The group of 25 + guards correspond to a Value of +14. If you subtract the + degrees of success and 3, you get +9. The indicate that it's equivalent to a + Measure of 8. So, 8 guards have fail their roll into a + dramatic end. If the roll have give a failure at -3, the + final value will then be (+14 - 3 - 3 =) +8, and so only 6 + guards will have succeed to jump over the + gap. It will have take a degrees of success of +12 for every + guards to pass the gap. + + + When you roll the dice for a group, it is good advice to + only make closed difference + roll (±d10). The great range of open rolls create must + of the time incredible catastrophe or miraculous prowess, + instead of normal result. +

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+ Group Degrees of Success + + The precedent method is very exact if you apply the + theoretical probability curve on which is based the Harmonies, + but which are only an approximation of the real dice dispersion. + A similar method permit not only to be nearer than the real + value, but also to calculate the level of success of each + individual or, to be exact, to know the number of individual for + each level of success. It is, however, much more longer and + complex. It will be to the Game Master to choose which of both + it will used, but must stay consistent for their players. + + The method need the same + conditions then the preceding method (homogeneous group) + and at least hundreds of individual if we want to detail each + level of success (the precision will be lesser elsewhere). The + Game Master begin again with a roll for the whole group. She + then convert the number of individuals in Value and subtracts + the number of points indicate in , in + function of the difference between the degrees of success of the + roll and the one we are interested in. The first row of the + table represent the difference between the degrees of success of + the roll and the one we want to know, the second row show the + value to subtract to obtain the Value of the number of + individuals having exactly this number of degrees of success, + and the last one give the value to subtract to obtain the number + of individual that have at least this + difference in number of degrees of success. The result can then + be converted into a Measure and you got the number of + individuals having this number of degrees of success plus or + minus the difference. For columns with fraction (like -2.5), + you must take the average of the two adjacent values. For + example, at -2.5, you must take the average of the Measure of -2 + and -3. + + + Groups Degrees of Success + + + + + + + + + + + + + + + + difference + 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + + + exactly this difference + -10 + -10.5 + -11 + -11.5 + -12 + -13 + -14 + -15 + -17 + -20 + + + this difference or more + -2.5 + -3.5 + -4.5 + -5.5 + -7 + -8 + -10 + -12 + -15 + -20 + + + +

+ + + Group Degrees of Success + + We have a group of 300 soldiers (Value of +25) who get a + +2 success margin. With +25 - 10 = +15, so 30 soldiers that + got exactly this success margin (+2). For the number of + soldiers who got +1 or +3 (1 point of difference), we must + take the Measure of -10 (which we already have: 30) and -11 + (which is the same as the column 2, which we still don't + know). So, for a difference of 2 points, we have +25 - 11 = + +14, or 25 individuals with 0 degrees of success, and another + 25 with +4 degrees of success. We can now take the sum of 30 + and 25, which is 55, that we can split in two: there will be + 28 soldiers with +1 degree of success, and 27 with +3 degrees + of success. + + + The last row ask for more explanations. If you're looking + for the number of individuals with +3 or more degrees of + success, and that you roll a +2, it's easy. You just have to + convert for a difference of +1 or more. But if you were looking + for those with 0 or more, you're in trouble! You can take only + those with 2 points of difference or more, because you will only + get those with +4 or more! What's you really looking for is + those with +0 (2 points of difference exactly), +1 (1 points of + difference exactly) and +2 and more (0 or more points of + difference). But a shorter way will be to looking for the + opposite. Find all of them that get -1 or less (3 points of + difference and more) and subtract them from the total of + individual in the group to find those who get +0 and + more. + + + Group Degrees of Success 2 + + With the same group as before, we are looking for the + number of those that got +0 and more degrees of success. This + represent a difference of 2 points which include the result of + the roll. We can then find those who got less than zero + degrees of success (a difference of 3 points or more) and + subtract it to the Measure of the group. The column 3 got us + with -5.5, which mean that we must take the average of -5 and + -6. +25 - 6 = +19, or 80 individuals. +25 - 5 = +20, or 100 + individuals. The average is (100+80)/2 = 90 soldiers who has + less than zero degree of success. On the initial group of 300 + soldiers, that's mean that (300-90) = 210 soldiers have got +0 + or more. Using the method view in the preceding section, we + would get 100 individuals that have failed (+25 -2 -3 = +20), + so 200 individual that have succeed. + + + + + Choosing between the two methods + + The maximum error is 6% or less on the total of + individuals for the first method, and less than 1% for the + second method. You have to choose between a more precise but + longer roll, or a quickest but less exact one. At the same + time, You can choose to only take the lowest Value instead of + calculating the average when you got an .5 factor to subtract. + Again, this is just a compromise on speed and + exactitude. + + + +