[Freeciv-Dev] Civ2 vs. Freeciv differences

[Greg Wooledge <wooledge@xxxxxxxxxxx>]

These are the Civilization II "features" not present in Freeciv (at
least the ones I've observed and which I can also remember right now).
Many are not worth implementing (like the strict river travel rules),
but some are probably simple oversights (like the Barracks II
obsolescence advancement).

* Engineers and Settlers may combine efforts.  Doing so may make
  a terrain modification happen immediately, possibly freeing the
  Settler or Engineer who was working on that modification (but of
  course the second Settler/Engineer now has no movement points).  This
  is particularly effective with pollution cleanup and major terrain
  alterations (see below), but even mining and irrigation can benefit
  greatly.

  This can probably be done fairly easily by simply adding the
  activity_count for all units on the tile performing the proper
  activity, rather than checking individual units to determine whether
  one of them has successfully completed its activity.  (This can
  still occur in update_unit_activity(); there will just be a little bit
  of redundant caclulation if multiple units are both working together;
  every turn, each unit will be checked, which will then check the
  tile and discover the other units and add their activity.  Since
  this happens for each unit, the computation is done N times if there
  are N units working together.)

  I don't know whether Civ2 combines pillaging efforts.  I generally
  don't use pillaging.

* Building a unit or city improvement makes it available at the end of
  the next turn, not the beginning.

* Excess production isn't saved when something is built.  This was done in
  Freeciv to work around a loophole which makes micromanagement of a city
  more useful than it should be (advantage for AI, disadvantage for human).

  However, the problem is that on the turn after something has just
  been built, the next thing in line is partially started, instead of
  having 0 shields, so it can be purchased immediately for less than
  half what it would have cost under Civ2 rules.  It might be better to
  introduce some sort of new rule that states, "Buying units/improvements/
  wonders costs double if the unit/improvement/wonder has been in production
  for only 1 turn." instead of the current "Buying ... costs double if it
  has 0 shields."  This is not an elegant rule, though, so I'm sure it has
  problems of its own.

* Engineers (not Settlers) may make terrain alterations in addition to
  the current irrigation/mining effects.  The list was posted to the
  freeciv-dev mailing list.  This is *extremely* useful after global
  warming produces Deserts everywhere; in Freeciv (and Civ1) Deserts
  are eternal, but in Civ2 they can be altered to Plains.

* Irrigated terrain may be irrigated a second time to produce "farmland",
  which is the only time the Supermarket is useful.  (In freeciv, the
  need for farmland is omitted; the Supermarket produces 50% more food on
  all land squares, not just farmland squares.)  This can only be done
  once the Refrigeration advance is known.

* Rivers are not just Rivers; they're some other base terrain type with a
  river "feature" overlaid on them (e.g., Plains with a river, or Forest
  with a river).  I'm not sure of the exact Civ2 game effect of a river.

  Speaking of rivers, Civ2 allows the 1/3 movement point river travel
  bonus only when following the river (and you can't even cut corners);
  freeciv allows it for any movement from one River tile to another,
  which is only an approximation.

* Each terrain type has two different special resources, not just one.
  I'm not sure how Civ2 handles terrain type modifications with respect
  to specials; freeciv simply sets a bit flag to determine whether a
  given tile has a special or not, and this flag remains set (or clear)
  across all terrain modifications.  I haven't played Civ2 enough to
  tell whether something similar happens there, and if so, how the game
  determines which of the two specials to use.

* Certain advances, city improvements and units are not available.  The
  Fundamentalism government type is not available (it's too powerful).
  However, I'm not convinced that all of the other omissions are
  unbalanced; for example, Elephants (Polytheism) are A4/D1/M2/H1/F1, which
  is only 1 attack point more powerful than a Chariot (and is identical to
  the Civ1 Chariot).  I believe they also cost more shields than
  Chariots.  Crusaders (A5/D1/M2/H1/F1, Monotheism) are similarly debatable;
  they're just Knights with A5/D1 instead of A4/D2.

  I believe the rationale of Civ2 in introducing these units was both to
  mimic true human history (Western religion = war, fear, death), and to
  allow players to have a few decent warlike units without needing to
  divert research time to explicitly warlike development paths.

  I never learned what Environmentalism or the Solar Plant do.  It appears
  that the Solar Plant may be built in addition to a Power/Nuclear/Hydro
  Plant.

  It makes sense not to offer the Eiffel Tower wonder, since the AI has
  no concept of peaceful relations.  It only knows war.

* In addition to normal corruption, Civ2 features "waste", which is a loss
  of production shields in addition to the lost trade.  I'm not sure how
  this is computed, but it seems to grow in proportion to corruption.

* Barracks (II) are made obsolete by Mobile Warfare (Armor), not
  Combustion.  (Civ1 didn't have Mobile Warfare, and made Barracks
  obsolete upon learning Combustion.)

* Units in a city with a healing improvement (Barracks, Port Facility,
  Airport) don't become fully healed unless they pass (' ') an entire
  turn in the city.  And of course the United Nations wonder is completely
  different (see Eiffel Tower above).

* Civ2 is more generous with Partisans.  They are produced under far
  less strict conditions than those of Freeciv (in particular,
  Partisans are produced under governments other than Democracy and
  Communism, and for cities not originally built by the player, but I
  don't know the exact rules).

* Spies which survive their assignment are sent to the nearest friendly
  city, not to their home city.

  Does Freeciv produce veteran Spies if the city has a Barracks?  Civ2
  does not; veteran status of a Spy is achieved only after a successful
  mission (or possibly under Communism; I'd have to check).  Of course,
  a Spy is worthless in combat, so the veteran status means something
  completely different for Spies; I believe it gives them an increased
  chance of success on future missions (and possibly increased chance of
  defending against attacking Spies?).