actgroup.en.sgml
brancharpeges
changeset 0 1397c2bfefa2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/actgroup.en.sgml	Mon Dec 26 19:21:22 2005 -0500
@@ -0,0 +1,383 @@
+<?xml version="1.0"?>
+<!DOCTYPE section PUBLIC "-//OASIS//DTD DocBook XML V4//EN"
+        "/usr/share/sgml/docbook/dtd/xml/4.2/docbookx.dtd"
+[
+  <!ENTITY % struct-dtd SYSTEM "struct.dtd">
+  %struct-dtd;
+]>
+<section id="sactgroup" revision="$Revision: 1841 $ $Name$"
+  vendor="1.19" xmlns:xi="http://www.w3.org/2003/XInclude">
+
+  <title id="stactgroup">Group Actions</title></title>
+
+  <para>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 <emphasis
+    role="ironic">efficient</emphasis>.  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 <link linkend="scombinaisons">compute the
+    total power of a group</link>, <link linkend="sjetgroupe">count
+    the number of success</link> in a group with only one roll, and
+    even <link linkend="sjetdist">determine the degrees of
+    success</link> of each individual character of the group.</para>
+
+  <section id="scombinaisons">
+    <title id="stcombinaisons">Values Combination</title>
+
+    <para>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 <emphasis>combine</emphasis> 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.</para>
+
+    <para>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.</para>
+
+    <procedure id="pcombinaison">
+      <title id="ptcombinaison">Calculation of Values Combination</title>
+      <step id="pscombind">
+        <para>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).</para>
+      </step>
+      <step id="pscombgrpident">
+        <para>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.</para>
+      </step>
+      <step id="pscombgrpdiff">
+        <para>Take the two groups with the least Value.</para>
+        <substeps>
+          <step id="pscomb1a3">
+            <para>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.</para>
+          </step>
+          <step id="pscomb4a6">
+            <para>If the difference is between 4 and 6 included,
+              combine them and give the Value of the strongest +1.</para>
+          </step>
+          <step>
+            <para>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.</para>
+          </step>
+        </substeps>
+      </step>
+      <step id="scombfinal">
+        <para>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.</para>
+      </step>
+    </procedure>
+    
+    <para>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.</para>
+
+    <example id="xcombinaison">
+      <title id="xtcombinaison">Group Value Combination</title>
+
+      <para>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:</para>
+
+      <orderedlist>
+        <listitem>
+          <para>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.</para>
+        </listitem>
+        <listitem>
+          <para>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.</para>
+        </listitem>
+        <listitem>
+          <para>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.</para>
+        </listitem>
+        <listitem>
+          <para>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.</para>
+        </listitem>
+        <listitem>
+          <para>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
+            <emphasis>combined</emphasis> Body Attribute of +9.
+        </listitem>
+      </orderedlist>
+
+      <para>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.</para>
+    </example>
+  </section>
+      
+  <section id="sjetgroupe">
+    <title id="stjetgroupe">Rolling dice for a group</title>
+      
+    <para>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 <anchor
+      id="refjgrpcond"/>homogeneous (no more then 5 points of
+      difference in their Competency Level for this particular action)
+      et that the roll is a <link linkend="sactsimple">simple
+      action</link>, 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
+      <emphasis>failed</emphasis> their roll.  Elsewhere, it represent
+      the number of individual that succeed their roll.</para>
+
+    <example id="xreussitegroupe">
+      <title>Simple Group Roll</title>
+
+      <para>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 <xref
+        linkend="tmesures"/> 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 <emphasis>succeed</emphasis> to jump over the
+        gap.  It will have take a degrees of success of +12 for every
+        guards to pass the gap.</para>
+    </example>
+    
+    <para>When you roll the dice for a group, it is good advice to
+      only make <link
+      linkend="sjetdifference"><emphasis>closed</emphasis> difference
+      roll (±d10)</link>.  The great range of open rolls create must
+      of the time incredible catastrophe or miraculous prowess,
+      instead of normal result.</para>
+  </section>
+
+  <section id="sjetdist">
+    <title id="stjetdist">Group Degrees of Success</title>
+    
+    <para>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.</para>
+
+    <para>The method need the <link linkend="refjgrpcond">same
+      conditions</link> 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 <xref linkend="tjetdist"/>, 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 <emphasis>at least</emphasis> 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.</para>
+
+    <table frame="all" id="tjetdist">
+      <title id="ttjetdist">Groups Degrees of Success</title>
+      
+      <tgroup cols="11" align="center">
+        <colspec colnum="1" colwidth="1.5in" align="right"/>
+        <colspec colnum="2" colwidth="0.5in"/>
+        <colspec colnum="3" colwidth="0.5in"/>
+        <colspec colnum="4" colwidth="0.5in"/>
+        <colspec colnum="5" colwidth="0.5in"/>
+        <colspec colnum="6" colwidth="0.5in"/>
+        <colspec colnum="7" colwidth="0.5in"/>
+        <colspec colnum="8" colwidth="0.5in"/>
+        <colspec colnum="9" colwidth="0.5in"/>
+        <colspec colnum="10" colwidth="0.5in"/>
+        <colspec colnum="11" colwidth="0.5in"/>
+        <tbody>
+          <row>
+            <entry>difference</entry>
+            <entry>0</entry>
+            <entry>1</entry>
+            <entry>2</entry>
+            <entry>3</entry>
+            <entry>4</entry>
+            <entry>5</entry>
+            <entry>6</entry>
+            <entry>7</entry>
+            <entry>8</entry>
+            <entry>9</entry>
+          </row>
+          <row>
+            <entry>exactly this difference</entry>
+            <entry>-10</entry>
+            <entry>-10.5</entry>
+            <entry>-11</entry>
+            <entry>-11.5</entry>
+            <entry>-12</entry>
+            <entry>-13</entry>
+            <entry>-14</entry>
+            <entry>-15</entry>
+            <entry>-17</entry>
+            <entry>-20</entry>
+          </row>
+          <row>
+            <entry>this difference or more</entry>
+            <entry>-2.5</entry>
+            <entry>-3.5</entry>
+            <entry>-4.5</entry>
+            <entry>-5.5</entry>
+            <entry>-7</entry>
+            <entry>-8</entry>
+            <entry>-10</entry>
+            <entry>-12</entry>
+            <entry>-15</entry>
+            <entry>-20</entry>
+          </row>
+        </tbody>
+      </tgroup>
+    </table>
+
+    <example id="xjetdist">
+      <title>Group Degrees of Success</title>
+      
+      <para>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.</para>
+    </example>
+    
+    <para>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.</para>
+
+    <example id="xjetdist2">
+      <title>Group Degrees of Success 2</title>
+      
+      <para>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.</para>
+
+    </example>
+
+    <note userlevel="adv">
+      <title>Choosing between the two methods</title>
+      
+      <para>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.</para>
+
+    </note>
+
+  </section>
+</section>
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