AmigActive 25/AACD 25.iso/AACD/Games/Freeciv/README.rulesets

Text File | 2001-08-17 | 12.7 KB | 351 lines

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                       Freeciv Rulesets
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          (Originally by David Pfitzner, [e-mail])

Quickstart:
-----------
 Rulesets allow modifiable sets of data for units, advances, terrain,
 improvements, wonders, nations, cities, governments and miscellaneous
 game rules, without requiring recompilation, in a way which is
 consistent across a network and through savegames.  (In the future
 there could be other categories of rulesets.)

- To play Freeciv normally: don't do anything special; the new
  features all have defaults which give the standard Freeciv
  behaviour.

- To play a game with rules more like Civ1, start the server with:
       ./ser -r data/civ1.serv
  (and any other command-line arguments you normally use; depending on
  how you have Freeciv installed you may have to give the installed
  data directory path instead of "data").

  Start the client normally.  The client must be network-compatible
  (usually meaning the same or similar version) but otherwise nothing
  special is needed.  (However some third-party rulesets may
  potentially require special graphics to work properly, in which case
  the client should have those graphics available and be started with
  an appropriate '--tiles' argument.)

  As well as a Civ1 style as above, Freeciv now has a Civ2 style
  similary, although currently it is almost identical to standard
  Freeciv rules.

  Note that the Freeciv AI might not play as well with rules other
  than standard Freeciv.  (See notes below.)

The rest of this file contains:

- More detailed information on creating and using custom/mixed
  rulesets.

- Information on implementation, and notes for further development.

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Using and modifying rulesets:
-----------------------------

Rulesets are specified using new server options.  The command above
of "./ser -r data/civ1.serv" just reads a file which sets these
options (as well as a few of the standard server options).
The new server options are:

        techs, governments, units, buildings,
        terrain, nations, cities, game.

They are special server options in that they take string values, but
otherwise the behave like normal server options.  Eg, try the server
command "explain techs".

For each of these options, the value of the option specifies a
subdirectory of the Freeciv data directory, containing a file
name techs.ruleset, units.ruleset, buildings.ruleset, etc.

Eg, the commands:

    set techs default
    set governments default
    set units civ1
    set buildings custom
    set terrain civ2
    set nations default
    set cities default
    set game custom

would specify the files:

    data/default/techs.ruleset
    data/default/governments.ruleset
    data/civ1/units.ruleset
    data/custom/buildings.ruleset
    data/civ2/terrain.ruleset
    data/default/nations.ruleset
    data/default/cities.ruleset
    data/custom/game.ruleset

(This is just an example, and may not give very sensible rules; the
directory data/custom and the file data/custom/buildings.ruleset do
not exist in standard Freeciv.)

The ruleset files in the data directory are user-editable, so you can
modify them to create modified or custom rulesets (without having to
recompile Freeciv).  It is suggested that you _don't_ edit the
existing files in the "default", "classic", "civ1" and "civ2"
directories, but rather copy them to another directory and edit the
copies.  This is so that its clear when you are using modified rules
and not the standard ones.

The format used in the ruleset files should be fairly
self-explanatory.  A few points:

- The files are not all independent, since eg, units depend on
  advances specified in the techs file.

- Wonders and city improvements have a new field, "variant".  This
  allows limited changes to the effects of specific wonders and
  improvements, where such changes have been implemented.  See the
  "TODO Variants" section below for which variant effects which have
  been implemented so far.

- Units have a new field, "roles", which is like "flags", but
  determines which units are used in various circumstances of the
  game (rather than intrinsic properties of the unit).
  See comments in common/unit.h

- The [units_adjust] section of the units file deserves some
  explanation.  It contains the entries:

    max_hitpoints, max_firepower, firepower_factor.

  The first two entries (unless zero) override the hitpoints and
  firepower entries for individual units, as a convenience.
  The value of firepower_factor is used when combat is resolved:
  All combat firepower values are multiplied by firepower_factor,
  which means that the effective hitpoints of any unit is really
      (hitpoints/firepower_factor).
  Actually, it is these effective hitpoints which are report to the
  client for all hitpoint values.
  (This complicated setup is so that the AI calculations don't
  blow up when using Civ1 rulesets.)

Properties of units and advances are now fairly well generalised.
Properties of buildings are still rather inflexible.

NOTE:  There is much in the rulesets that is not completely
implemented.  Be sure to read Restrictions and Limitations, below.

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The civstyle option:
--------------------

The server option civstyle still exists, but its only current use is
to determine how much of the map is revealed when the Apollo Program
id built.

The civstyle option will be removed in the near future.

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The AI:
-------

An important caveat regarding rulesets is that while rulesets allow
considerable flexibility, the AI has been designed and tested using
"standard Freeciv" (effectively Civ2) rules.  So the AI may not do as
well with modified rules.

Some changes to the AI have been made to try to take some of the
ruleset changes into account, and the combat calculations have been
fudged to try to avoid core dumps, but in general you should not
expect the AI to work as well with non-default options (where Civ1 is
definitely included in "non-default").

Examples of problems which have not been fixed:
- Units not having hitpoints in Civ1 can make a big difference to
  appropriate combat strategies.
- City walls are sufficiently different (increased build cost, and
  upkeep; and effect vs sea) to require different handling?
- Without the Harbour and Offshore Platform improvements, cities with
  many ocean squares are much more limited in Civ1.
- Wonders which only work on a single continent are not given special
  consideration by the AI.

Hopefully this situation can be improved in the future, but the more
flexible the rules, the harder to write a good AI...

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Restrictions and Limitations:
-----------------------------

units.ruleset:

  Unused entries:

    - uk_gold

  Restrictions:

    - At least one unit with role "FirstBuild" must be available
      from the start (i.e., tech_req = "None").

    - There must be units for these roles:
      - "Explorer"
      - "FerryBoat"
      - "Hut"
      - "Barbarian"
      - "BarbarianLeader"
      - "BarbarianBuild"
      - "BarbarianBoat"  (move_type must be "Sea")
      - "BarbarianSea"

    - There must be at least one unit with flag "Cities".

    - Every unit with flag "Cities" must have also flag "Settlers".

  Limitations:

    - These unit flag combinations won't work:
      - "Diplomat" and "Caravan"

buildings.ruleset:

  Unused entries:

    - bldg_req
    - terr_gate
    - spec_gate
    - equiv_range
    - equiv_repl
    - sabotage
    - effect

nations.ruleset:

  Unused entries:

    - attack
    - expand
    - civilized
    - advisors
    - tech_goals
    - wonder
    - government

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Implementation details:
-----------------------

This section and following section will be mainly of interested to
developers who are familiar with the Freeciv source code.

Rulesets are mainly implemented in the server.  The server reads the
files, and then sends information to the clients.  Mostly rulesets
are used to fill in the basic data tables on units etc, but in some
cases some extra information is required.

For units and advances, all information regarding each unit or advance
is now captured in the data tables, and these are now "fully
customizable", with the old enumeration types completely removed.  For
improvements and wonders, each one has a largely unique effect, so the
effects themselves are still hardwired in the code.  The "variant"
field now allows some flexibility, though the effects themselves must
still be hard-coded.  There are some plans to improve this situation.

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TODO:
-----

- More improvement and wonder variants for Civ1 (see next section).
- Other alternative (non-Civ1) variants?  (If desired.)
- Better: Scrap variants completely and do something more general...

- Fix up AI dynamic government choice code.
- Work on making the AI handle non-default cases better.
- Could have other information to help the AI?
  Eg, scores for units/techs/buildings, to help the AI know which
  ones to prefer?

- Rulesets for: time progression, ...?

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TODO Variants:
--------------

First, those variants which have been implemented:
(Note Variant=0 should always be "standard Freeciv" effect.)

Barracks:     Variant=0: just works for ground units (Civ2)
         Variant=1: works also for air and sea units (Civ1)
Barracks II, Barracks III, Sun Tzu:
         These use the same variant value and effect as
         Barracks.
City Walls:      Variant=0: only applies against land and heli units
         Variant=1: applies against sea units too
Police Station:  This uses the same variant value and effect as
         Women's Suffrage (see below).

Pyramids:     Variant=0: counts as Granary in every city (Civ2)
         Variant=1: allows all government types and there is
                no transition anarchy (Civ1)
United Nations:  Variant=0: units regain extra hp per turn (Freeciv)
         Variant=1: allows all government types and there is
                no transition anarchy (Civ1) (see note(*))
Hoover Dam:     Variant=0: works on all cities owned
         Variant=1: only works for cities on the same
                continent as where the wonder is built
J.S. Bach:     Variant=0: works on all cities owned
         Variant=1: only works for cities on the same
                continent as where the wonder is built
Women's Suff.:   Variant=0: -1 unit-unhappy per City (-2 under
                Democracy) (Freeciv)
             Variant=1: -1 unit-unhappy per Unit (Civ1)
Magellan's Exp.: Variant=0: gives sea units 2 extra move points
         Variant=1: gives sea units only 1 extra move point
Great Wall:     Uses same variant and effect as City Walls.
Leo's Workshop:  Variant=0: Upgrades one obsolete unit per game turn.
         Variant=1: Upgrades all obsolete units each turn.
Michelangelo's:  Variant=0: same as a Cathedral in every city
         Variant=1: doubles effect of cathedrals

Other differences between Civ1 and Civ2/Freeciv which have not been
implemented as variants:

Copernicus' Obs.: Freeciv: science output +50% in a city
          Civ1:    doubles knowledge production in city, after
               all other effects.
Isaac Newton's:   Freeciv: science output +100% in a city
          Civ1:    "increases effects of Libraries and
               Universities" - by how much??

There are other more minor Civ1/Civ2/Freeciv differences, which
could be handled using variants, for:
    Courthouse
    Cure For Cancer
    Hanging Gardens
    Lighthouse

Notes:

Aqueduct and Sewer System:
   The maximum sizes for cities without these improvements is handled
separately, without using variants.  This leaves variants available
if some other effects are desired.

Colosseum, Cathedral, Temple:
   Note that the technology effects on the effectiveness of these
buildings are not handled by variants, but by specially noting the
techs; see game.rtech fields cathedral_plus, cathedral_minus,
colosseum_plus, and temple_plus.  (Also applies to Michelangelo's.)

(*) United Nations:
    I'm not sure what to do here: the diplomatic effect of Civ1,Civ2
isn't appropriate for multiplayer Freeciv, and the hp effect of
Freeciv isn't appropriate for Civ1 (no hitpoints).  The govchange
effect seems reasonable -- note there is no Statue of Liberty in
Civ1, and Pyramids, which has the same effect in Civ1, becomes
obsolete.  Alternatively a Suffrage-like effect would seem sensible:
your population is more willing to go to war if it has the sanction
of the United Nations!

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