   This document is compilation of bugs, undocumented features, tricks and traps (as SMAC Academy names it) for the game Sid Meier's Alpha Centauri (SMAC) and expansion Alien Crossfire (SMAX), that can be also referred to as SMACX for both, AC for vanila, ACX for expansion, etc.
   
   Version: 001.001
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Classifications:

bug, serious
bug, minor
exploit
annoyance, serious
...

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1)  Probe SE bug. City "Mind Control" probe bug.
Classification: bug, serious
Status: (Feb., 15, 2009), Fixed

Description (from SMAC Academy):
A probe value of 4 or above does not work but is equal to a probe value of 0. This goes both for global proba value and city specific probe value. For the Angels faction this can be a major problem in the late game as they get an automatic Free covert ops Centre giving each city +2 probe with discovery of pre-sentient algorithms and having +2 from start this means the covert ops centre puts them back at 0.
Notes:
If you have University with knowledge so -4 PROBE, it will act like +0 PROBE. So, in effect you actually get a better PROBE score by making it more negative. (by Scient)

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2) Air interceptor could potentially cause a crash.
Classification: bug, serious
Status: (Feb., 15, 2009), Fixed

Description (by Mart):
When processing a turn an air unit is scrambled to defend against another air attack, game crashes.

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3) Caretakers colony pod bug.
Classification: bug, serious
Status: (Feb., 15, 2009), Fixed
(credit to WBird784 for patch data) 

Description (by Scient):
In the vanilla game if you open up Design Workshop as Caretakers and switching back and forth between colony pod and other "equipment" you can cause text in "special ability" to become overwritten (memory overflow) and crash once you exit Design Workshop.

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4) Multiple airdrop.
Classification: bug, serious
Status: (Feb., 15, 2009), Fixed

Description (from SMAC Academy):
Normally, a unit with drop pods can only make one air drop per turn and must start the turn in a base or airbase without having moved to perform the air drop. Activating a unit with drop pods, right-clicking on another square, and selecting the air drop command from the menu will always allow the unit to make the air drop as long as the square is within air drop range; this allows the unit to make an infinite number of air drops in a turn that don't have to start in a base or airbase and that don't depend on whether or not the unit has any movement points remaining. Using this procedure, drop infantry can perform an air drop, attack an enemy unit, and perform another air drop back to safety.

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5) Instant elite morale.
Classification: bug, serious
Status: (Feb., 15, 2009), in progress

Description (by SMAC Academy):
Units can be instantly upgraded to elite by setting them on patrol with 3 waypoints. That is (when it's the unit's turn to move), hit "P", click on a square near the unit and hit the spacebar. Repeat the last two steps two more times. The unit may or may not take off on its patrol, but it will upgraded to elite. Native units will become demon boils. This works in SMAX, fully patched. Obviously a cheat.

Notes:
...

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6) Repair ability.
Classification: bug, serious
Status: (Feb., 15, 2009), ...

Description:
Ability does not work. Transports with it heal other units the same as transports without this ability.
Note:
When testing, remember that The Nano Factory secret project gives faster healing to units in field. Can be mistakenly interpreted, as repair works.

Cause guess:
- engine does not check for ability presence in the unit
- ...
Solution:
- ...

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7) Drone display bug.
Classification: annoyance, serious
Status: (Feb., 15, 2009), ...

Description:
Sometimes bases incorretly display drones in a base in the lower citizens' slot. The display of drones is however correct on the psych screen and F4 screen.
Note:
It's not a game breaking bug, but increases micromanagement for players, who need now separately check all bases for true drones presence. This causes that some players resign from playing SMAC.

Cause:
...
Solution:
...

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8) Activate the scenario editor in a PBEM.
Classification: bug, serious
Status: (Feb., 15, 2009), ...

Description (by Chaos Theory):
Ability to activate the scenario editor for a PBEM (CGN 16)
(by SMAC Academy):
Sometimes a password-protected hot-seat/pbem save file will open in the Scenario Editor after you enter your password enabling the player to edit the game with the scenario editor. It is not clear exactly what causes this behaviour. The score screen (F8) will say "CHEATED" after somebody does this in the game. (tetunge)
Note:
A serious bug, a player can unintentionally see uncovered map in muliplayer. Game breaking.

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Below is SMAC Academy list, for reference only, as copied from the site
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   1.   Colony pods can be added to an existing base to increase the base population by 1 using the join base command (b). This operation can be used to increase the size of the base beyond the limits imposed by lack of hab complexes/domes.
   2. Normally, a unit with drop pods can only make one air drop per turn and must start the turn in a base or airbase without having moved to perform the air drop. Activating a unit with drop pods, right-clicking on another square, and selecting the air drop command from the menu will always allow the unit to make the air drop as long as the square is within air drop range; this allows the unit to make an infinite number of air drops in a
      turn that don't have to start in a base or airbase and that don't depend on whether or not the unit has any movement points remaining. Using this procedure, drop infantry can perform an air drop, attack an enemy unit, and perform another air drop back to safety.
   3. A unit will always survive an air drop; the air drop damage will be reduced to preserve the final hit point.
   4. AI players have no intelligence when it comes to trading bases with human players. They will often trade their best bases for newly built size 1 bases in the middle of a desert.
   5. Submissive AI players can be forced into negative energy reserve balances by demanding that they trade their cash for technology.
   6. Missiles can be given to AI players who can use the infinite range missile bug to attack enemies without being limited by range.
      note: the infinite range missile bug is a bug that allows the AI to use missiles against bases regardles of ther distance. 
   7. If the "do or die" game option is turned off, it is possible to profit from destroying all of your units to restart in a different location. Most factions will receive an extra terraformer by doing this while Morgan will also get a synthmetal sentinel and +100 energy reserves.
   8. Boreholes can only be contructed in land squares where all adjacent land squares are at the same elevation "level" or higher and do not contain boreholes. It used to be possible to build boreholes adjacent to each other by having them built at the same time, but this has been fixed in the latest patches. (MoSe)
   9. Any rivers flowing into a square containing a borehole will end there since the water disappears into the borehole. (DilithiumDad)
  10. A borehole on the west coast increases moisture levels to the east. A borehole anywhere else decreases moisture in the surrounding area. (DilithiumDad)
  11. Drill to aquifier is not allowed in squares adjacent to an existing river. It is possible to create rivers in adjacent squares by performing the drill to aquifier operation in both squares at the same time. (MoSe)
  12. River courses are partly random (will be different each time); rivers will avoid rocky squares and will occasionally run uphill for one tile. (DilithiumDad)
  13. Supply crawlers collecting resources in squares outside of bases receive the benefits of facilities and secret projects in their home bases that increase the amount of resources collected in a square. Example: A supply crawler collecting nutrients in a forest square for a base containing a Tree Farm and a Hybrid Forest would collect 3 nutrients instead of 1. The same is true for social engineering choices where an economy setting of 2 or higher would increase supply crawler energy collection by +1 energy each. (DilithiumDad)
  14. It is possible to set home base (Control-h) for a unit to be the base of another faction when the diplomatic stance is pact. The unit will then require no support from either faction. (MoSe)
  15. When a land unit is unloading from a transport in a sea square to a land square, it will always cost only 1 movement point regardless of the terrain in the land square, including rocky, forest, and fungus squares. The rumor is that old versions of SMAC would cost 2 movement points to unload into a rocky square. (MoSe)
  16. Sometimes a password-protected hot-seat/pbem save file will open in the Scenario Editor after you enter your password enabling the player to edit the game with the scenario editor. It is not clear exactly what causes this behaviour.
      The score screen (F8) will say "CHEATED" after somebody does this in the game. (tetunge)
  17. Biology Lab prevents a random event (Planet Blight) from causing all forests and farms in the 20 base production squares to be destroyed; if the base has a Biology Lab, then the random event will instead provide +1 nutrient per square for 10 years due to the discovery of a beneficial bacterium. (DilithiumDad)
  18. The designs for captured units can be modified in the design workshop. This allows the use of unit technology from the captured unit to make 
      different unit designs even though the technology is not known. (Usually referred to as "reverse engineering")
  19. Once Planetary Networks is discovered, the probe team design can be modified in the design workshop to make other speeder designs even though Doctrine: Mobility is not known.
  20. Probe team units that are in land squares can conduct probe operations against other land squares (units and bases). Probe team units that are in sea squares can conduct probe operations against other sea squares (units and bases). The exception to these rules is that foil/cruiser probe teams can always conduct probe operations against land squares. Air units can never be probed, including choppers. Examples: A probe foil in a land base (land square) can probe an adjacent scout patrol in a land square but cannot probe an adjacent gun foil in a sea square. A probe team on a transport foil in a sea square can probe an adjacent sea base but cannot probe an adjacent land base.
  21. Normally, air transports - including choppers - can only load and unload passengers in a base or airbase. However, choosing the unload ransport (Shift-u) command will allow the passenger to unload while the air transport is in flight. (MoSe)
  22. On the turn a terraformer completes its terraforming task, its "flag" will be grayed out indicating that it has moved. Clicking on and activating the terraformer will allow a new terraforming command to be issued to the terraformer with the correct number of turns to completion displayed. Clicking on and activating the terraformer again, cancelling its new orders; at this point, the terraformer will have regained one movement point. (MoSe)
  23. Drop units without an actual weapon cannot drop into the base production squares or zones of control of units of another faction unless the diplomatic stance is pact. (MoSe)
  24. If a pactmate has a needlejet in the same square as one of your empty transport ships, then it is impossible to load units onto the transport. If the transport ship is not empty (already has one or more passengers), then more units can be loaded without a problem. (MoSe)
  25. Selecting "Demand Withdrawal" from the commlinks menu for another human faction causes the AI to decide for that faction whether to comply with the request or declare vendetta based on the AI attitude of the faction. The human player who actually controls that faction will not make the decision. (LoD)
  26. When engaging in a probe team operation against another human faction, a window appears asking whether the victim wants to "declare vendetta" or "let off with a stern warning" - if treatied or whether to "cancel pact" or ""let off with a stern warning" - pacted. This window is appearing during the wrong player's turn. It is the one doing the probing not the victim who gets the screen and makes the decision. Etiquette dictates that the prober should choose "declare vendetta" or "cancel pact" unless prior approval has been received from the victim to choose something else. (MoSe)
  27. If an truce/treaty/pact is being negotiated with another human player and that player has accepted the deal, it is possible to perform an action that causes vendetta and then accept the deal to erase the vendetta before the other player has had a chance to respond to the vendetta. (MoSe)
  28. Wild mind worms fight at 1/2 strength before the year 2115. 
  29. If a needlejet starts the turn outside of a base (1 turn of fuel remaining), it doesn't move at all during the turn, a base/airbase/carrier
      appears underneath it during the turn, and one of the hold (h or shift-h) or sentry (l or shift-l) commands is given to the needlejet, then the needlejet will not refuel and will only have 1 turn of fuel when it leaves the base/airbase/carrier on a later turn. Needlejets that haven't moved only refuel if they use the skip turn (spacebar) command.
  30. Units normally take 20% damage when performing an air drop (26% for singularity reactor.) However, if the air drop is into a friendly base, the unit takes no damage.
  31. Units are not allowed to air drop into sea squares, including squares containing sea bases or sea transport units.
  32. Air units are NOT destroyed if the base they are in is destroyed (contrary to what the manual says.)
  33. Native units get a +50% attack bonus when attacking non-native units that are in fungus squares; this includes Locusts of Chiron attacking non-native air units that are in fungus squares. Non-native land units in a fungus square get a +50% defend bonus when being attacked by non-native units in a normal (not artillery) attack. These are the only combat modifiers for fungus squares.
  34. Artillery combat between a land unit and a sea unit is not to the death - there's only one round of combat.
  35. Sea units can attack each other using either long range fire (attack value vs attack value) or normal attacks (attack value vs defend value). Players should note that this means that a sea unit with a low attack value can be easily destroyed by another sea unit regardless of its armor value. (Long range fire is applied by from a distance of 1-2 squares pressing F and pointing to the other ship).
  36. A stack of units containing a needlejet in flight can only be attacked by a unit with the air superiority ability. The unit with the best defend value will be the defender of the attack, not necessarily the needlejet.
  37. Choppers and land units can attack multiple times per turn as long as they still have movement points remaining; each attack cost 1 movement point. All other units use up all of their remaining movement points when making an attack.
  38. Switching industry social engineering does not change the number of minerals in the minerals stockpile accumulated towards production of the next build item. Adding a supply crawler to a secret project or prototype under construction will add minerals to the minerals stockpile equal to the cost in minerals of the supply crawler using the current industry social engineering value, not the cost in minerals of the supply crawler when the supply crawler was built. Switching to a different social engineering setting and then switching back to the original setting in the same turn
      refunds the cost of the first switch for a net cost of zero energy. Putting all of these facts together creates the trick of building supply crawlers inexpensively using a good industry setting, switching to a bad industry setting with the associated energy cost, adding the supply crawlers to the secret project/prototype for more minerals than it cost to make them, and finally switching back to the good industry setting to produce the secret
      project/prototype inexpensively, getting a refund of the energy spent to switch to the bad industry setting as well.
  39. A +3 police setting allows a unit with the non-lethal methods ability to control 3 drones (1 plus 1 plus 1), NOT 4 drones (1 times 2 times 2).
  40. Social engineering settings for morale, planet, and probe do not take effect until the beginning of the player's next turn.
  41. When the social engineering setting for morale is -2 or less, units built in a base with a command center, naval yard, aerospace complex, or bioenhancement center will only receive 1 morale upgrade instead of 2, and this result is permanent for those units. (This is part of what the manual means by "modifiers halved.")
  42. When voting in the Planetary Council, it is possible to click on the portrait of the faction for a human player and be offered a chance by the AI to pay a bribe for the vote of that faction. The AI decides the bribe rather than the human player whose faction it is.
  43. When voting in the Planetary Council, the AI will take on the role of a human-controlled faction and offer a bribe to the person currently voting. The player whose faction is offering the bribe is not offering the bribe - the AI is doing it for them without their knowledge.
  44. If a base completes construction of a facility or secret project and its build queue is empty, then for that turn the base will accumulate energy as if production had been set to stockpile energy in addition to accumulating the usual amount of minerals.
  45. If a base completes construction of a unit and its build queue contains stockpile energy as the next item to build, then for that turn the base will accumulate energy as if production had been set to stockpile energy in addition to accumulating the usual amount of minerals.
  46. Production occurs before drone riots are checked. Thus, production of a police unit, facility, or colony pod can prevent an impending drone riot.
  47. Population growth occurs after production. If the conditions are right, a base can make a colony pod and grow back to its original size in the same
      turn.
  48. Population loss removes the citizen farthest on the right. If the base has any specialists, the lost citizen will be a specialist.
  49. If a worker (not a specialist) is lost due to population loss, the remaining workers will automatically be rearranged by the AI (even for human-controlled factions), usually to maximize nutrients.
  50. Normally, a base must have an Aerospace Complex to be able to build orbital facilities. However, if an Aerospace Complex is the item currently being built, then orbital facilities can be added to the build queue. If production is switched to something other than the Aerospace Complex, the orbital facilities remain in the build queue and will be built without the need for an Aerospace Complex.
  51. Population growth occurs before drone riots are checked. Thus, population growth can cause drone riots in the same turn.
  52. On Thinker difficulty, base facility maintenance costs are reduced by 1/3. On Transcend difficulty, base facility maintenance costs are reduced by 2/3. (This is fixed for SMACX with the patch.)
  53. Skunkworks allows switching of production from one unit type to a different unit type or from one facility to a different facility without losing any minerals for "retooling".
  54. When Planetary Transit System is completed, all bases that are less
      than size 3 will immediately grow to size 3.
  55. The Repair Bay special ability does not work.
  56. Building a prototype of a weapon, armor, or chassis also counts as a prototype for lower-valued (or equal) weapons, armors, and chassis. Example: Building a missile (6) prototype means that gatling lasers (5), impact (4), and lasers (2) will also be considered as having been prototyped. Chassis prototypes only count for the same types of chassis: air, sea, land. Thus, prototyping a needlejet means that choppers and gravships will not have to be prototyped; they are the same type - air - and they have the same chassis "value".
  57. Discovering Planetary Networks automatically prototypes the Speeder chassis.
  58. Discovering Doctrine: Flexibility automatically prototypes the Foil chassis.
  59. When upgrading units, the new unit design must have the same chassis as the old unit design.
  60. When upgrading units, the new unit design must have a weapon value greater than or equal to the weapon value of the old unit design. Noncombat units must have the same "weapon" as before.
  61. When upgrading units, the new unit design must have an armor value greater than or equal to the armor value of the old unit design.
  62. If the old unit design has the Heavy Artillery special ability, then the new unit design must have it, too. If the old unit is an air unit with Air Superiority ability, then the new unit must also have it. If the old unit is an air unit without Air Superiority ability, then the new unit must also not have it.
  63. Units can be upgraded individually as long as they have not yet moved during the turn, and upgrading in this way uses up all of the unit's movement points for the turn. All units of the same design can be upgraded at the same time using the design workshop; upgrading units with this method has no effect on the movement points of the units that are upgraded and can be done even for units that have already moved.
  64. Air Superiority needlejets in a base prevent air drops within 2 squares of the base. Air Superiority choppers in a base do NOT prevent air drops.
  65. The diplomatic status between factions must be vendetta for interceptors and Aerospace Complexes to prevent air drops.
  66. Units with an actual weapon (hand weapons or better) use none of their movement points when performing an air drop; they can move normally after the air drop. Units without a weapon use up all of their movement points when performing an air drop.
  67. Colony pods cannot build a new base unless they have movement points remaining. Colony pods can add to the population of an existing base by opening the base screen, activating the colony pod, and pressing "b", even when they have no movement points remaining.
  68. When a supply crawler is in a square not being used by a base, it can use the "convoy resources" action to sit in the square and collect all of one type of resource in that square for use by its home base each turn. Only one supply crawler can "convoy resources" in each square. 
  69. Supply crawlers can use the "convoy resources" action even if they have no movement points remaining. Click on the supply crawler on the map (not at the bottom of the screen) and select the action.
  70. Supply crawlers with no movement points left that are inside a base can use the "convoy resources" action. Open the base screen, activate the supply crawler, and press "o". The "convoy resources" action is also the action used to add a supply crawler to a secret project or prototype. A supply crawler that starts the turn in a base can be individually upgraded (using all movement points) and then added to a secret project all in the same turn using these steps. Players should note that upgrading crawlers to a more expensive design before adding them to a secret project costs only 1-2 energy per mineral added instead of the usual 4 energy per mineral for a secret project, making secret projects relatively inexpensive to build.
  71. Players have reported being able to "credit up" terraformers by doing terraforming in one square until it is one turn from completion and then moving the terraformer to a different square where the terraforming is completed instantly. Again, the latest patches may have eliminated this
      since most players now report that all terraforming effort is lost if a terraformer moves. (However, effort can be applied towards a different
      terraforming task as long as the terraformer doesn't move.) 
  72. Each save file contains all of the commlink communications between human players made during the game. This is the main reason that save files grow in size to the extent that they do. Unlike the rest of the save file which is encrypted, all commlink communcations are merely plain text appended to the end of the save file. Anyone opening the save file in a text editor can see all commlink communications that have been made during the game.
  73. A probe value of 4 or above does not work but is equal to a probe value of 0. This goes both for global proba value and city specific probe value. For the Angels faction this can be a major problem in the late game as they get an automatic Free covert ops Centre giving each city +2 probe with discovery of pre-sentient algorithms and having +2 from start this means the covert ops centre puts them back at 0.
  74. Units can be instantly upgraded to elite by setting them on patrol with 3 waypoints. That is (when it's the unit's turn to move), hit "P", click on a square near the unit and hit the spacebar. Repeat the last two steps two more times. The unit may or may not take off on its patrol, but it will upgraded to elite. Native units will become demon boils. This works in SMAX, fully patched. Obviously a cheat.
  75. When you have somehow (probe, EG, Gov, Pact) infiltration on other factions, you can open their basewindows in several ways, including clicking on the basename in their F4 listing. From inside the infiltrated basewindow, you can click anywhere - nothing happens, to correctly prevent that you inadvertently or maliciously alter another player's choices.
      But from the "Citizens" tab of the F4 advisor, you can click on the citizens icons of an "infiltrated" faction, and make them specialists. Or right-click, and revert them to workers.
      Even if you do it inadvertendtly and attmept to reset the ohter player's choices back:
      - the game won't necessarily pick the same kind of specialists the other player chose
      - the game won't necessarily put the workers on the same tile the other player chose
  76. One cannot fire artillery from a transport using the F button (long range fire) on the keyboard. One can however do it by right-clicking on the target square and selecting "long range fire".
  77. Units cannot be upgraded to PSI armor or PSI weapon even if they have no armor or no weapon.Upgrading to PSI armor can only be done by upgrading to a unit with better weapon and PSI armor. Example you cannot upgrade a 1-1-1 to a 1-?-1 but you can upgrade it to a 2-?-1. Same goes for PSI weapon. You cannot upgrade a 1-1-1 to a ?-1-1 but you can upgrade it to a ?-2-1.
      There is no way to upgrade to a ?-?-x unit should one desire to do so.

Note that using most of these in a MP game is prohibited.
Scenario editor bugs

   1. Map features are placed on or removed from the map using Control-Click, NOT Shift-Click.
   2. Do not start with a blank map when making a custom map; always start with a randomly generated map and then edit it. The map elevations are messed up when starting with a blank map, one result being that placing the first river (or popping one in a Unity pod) causes much of the land to sink below the ocean.
   
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Bugs from Chaos Theory list for Civ4 mod preparation.
For reference only
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Originally posted by Chaos Theory
For a while, PBEMs have referenced the bug list at http://www.civgaming.net/smac/acad_buglist.shtml

It seems rather old and unorganized to me, and with the looming possibility of recreating SMAC in Civ 4, some of the bugs/exploits that are sometimes allowed and sometimes disallowed may become points of contention. Should we recreate those exploits or take the opportunity to fix them?

Here I'll roughly classify bugs, exploits, and tricks from the CGN list and others I know of by severity, and updated with current information. This list is just a draft for now, and will need updates.

Game-breaking bugs, should never be allowed:

Ability to activate the scenario editor for a PBEM (CGN 16)

Inexpensive completion of several expensive builds (like projects) at once

Multiple airdrops using the right-click menu (CGN 2)

Trading bases with the AI (as opposed to extorting or gifting) (CGN 4)

If you have another player infiltrated, you can affect his workers via the F4 screen (CGN 75).

Under some circumstances, a faction can be suddenly erased and restarted elsewhere on the map with a few units, as if it had been liberated by a probe team.
(Several more of these are known to CMNs, but knowledge is restricted to prevent abuse)

Game-damaging bugs, should rarely if ever be allowed:

Reactivation of terraformers (CGN 22)

Sometimes, the AI will take an action in place of a player on another player's turn. This can happen when using "demand withdrawal" and when bribing a faction during council elections. Sometimes, the AI will spontaneously bribe you on behalf of a human player (CGN 25, 42, 43).

Probing a human player prompts the active player, rather than the victim, for a response (CGN 26). The active player is expected to declare vendetta unless the victim has asked otherwise.

Changes in a player's industry rating take effect immediately, allowing crawlers to be cashed for higher value at no cost (CGN 38). Note that TCP/IP games handle this differently.

Units can be instantly upgraded to elite by way of the patrol command (CGN 74).

Artillery can sometimes fire upon tiles more than 2 tiles away.

If "Do or Die" is off, it is profitable to self-destruct your faction (CGN 7).

Units can be self-destructed to cause damage to all units in adjacent tiles not in bunkers or bases. The damage caused is normally floor(weapon * reactor * .5). Thus, two 10-1-12*2 needlejets can destroy a cluster of fusion units in the open, regardless of the number or strength of the units. No notification is given to affected players, and damaging or killing units does not initiate a vendetta.

Probe SE values of +4 or higher are treated as +0 for most purposes. This leaves the Data Angels' bases vulnerable after discovering PSA, and receiving free Covert Ops Centers. Players are expected to honor the Angels' actual probe rating.

Initiating a vendetta against another player has no effect on pending diplomatic deals. Specifically, if one player has accepted a treaty or pact, the other player can initiate a vendetta, then end it on the same turn by accepting the pending deal (CGN 27).

The build queue can be abused in many ways, allowing facilities to be built without prerequisites (CGN 50), sea units to be built in landlocked bases, and other Bad Things.

The AI knows where all units are on the map. Placing air units "on alert" basically hands control over to the AI, which will use them to destroy enemy units the player had no way of seeing.

Game-altering bugs, sometimes allowable:

"Reverse engineering" stolen (or gifted) units in the design workshop allows access to weapons, armors, chassis, reactors, and special abilities not yet discovered (CGN 18).

As a result of reverse engineering, Planetary Networks essentially grants the rover chassis (CGN 19, 57).

A unit upgraded individually consumes its entire turn. Units upgraded via the design workshop can act normally. This can allow severe sneak attacks (CGN 63).

Aerospace complexes and interceptors do not prevent drops of non-hostile units. This can allow severe sneak attacks (CGN 65).

Secret projects normally cost 4 EC/mineral to hurry. Units normally cost 1-2 EC/mineral to upgrade. By upgrading supply crawlers, secret projects can be hurried for a reduced cost (CGN 70).

Under some circumstances, a terraformer can accumulate "credit" in safety, then move to a dangerous tile and hastily complete a terraforming project, before an opposing player can respond (CGN 71).

Artillery can only be fired from a transport via the right-click menu (CGN 76).

Colony pods can be added to bases to breach habitation limits (CGN 1).

The AI can sometimes trade more ECs than it has, leaving it with a negative balance (CGN 5).

Aquifers cannot normally be drilled adjacent to rivers, but if a former has already started drilling before an adjacent river appears, it will finish normally (CGN 11).

Boreholes cannot normally be constructed adjacent to lower terrain, but if terrain changes so that a borehole would be illegal, terraformers already working on a borehole will finish normally.

When a base finishes constructing a facility/project, or finishes a unit with "Stockpile Energy" next in the queue, the base's entire mineral yield for the turn will be converted into energy, and the surplus will also be applied (up to the 10 mineral cap) to the next build (CGN 44, 45).

Normally, changing production costs half the minerals accumulated after the first 10. If the item currently being produced is a unit, and that unit's design is retired, all accumulated minerals can be reassigned at no cost. Combining this with cashing in upgraded crawlers to contribute to prototypes yields the Maniac Manoeuvre, a way to rush all production for reduced cost.

Normally, air transports cannot unload in flight. However, using the keyboard shortcut will bypass this restriction (CGN 21).

Clicking on an unexplored tile will center the view there, unless a base is on that tile. In this way, bases can be located without exploration.

Dragging a path for a unit to follow will normally name the destination with coordinates. If the destination is a base, that base will be named instead, even if it hasn't been found yet.

Attacking a unit with an air unit can cause the defending faction to automatically intercept by moving a SAM needlejet from a nearby base to the attacked tile. If the two factions have the status of truce or treaty, the attacker can then choose not to declare vendetta and attack elsewhere, having drawn out a defender.

Native life can be captured by attacking it, but if "Confirm Odds" is on, the player is given a chance to back out of the attack after seeing whether the capture was successful.

Minor bugs, usually not worth the trouble to exploit:

Tree farms and similar facilities, when built after the first *pop*, increase the faction's clean mineral limit by one each. If those facilities are scrapped, the increase remains.

Specialists other than doctors (or their replacements) cannot normally be assigned to small bases, but if a base shrinks, any specialists already assigned remain unless reassigned.

Automated formers can build improvements in fungus tiles before that ability is granted by technology.

Bugs that give the user a disadvantage:

Needlejets that are upgraded (by the design workshop) while in flight will have many fewer movement points than normal, and will usually crash.

Fungal towers sometimes appear underneath units (usually crawlers). If one is killed while a crawler is on the same tile, the crawler is also destroyed.

If an airbase, base, or carrier appears under a needlejet that has used one turn of fuel, it will not refuel properly until it has moved again or skipped its turn (CGN 29).

Sometimes, after an artillery unit performs long range bombardment, a nearby enemy artillery unit will respond and "defend" against another, separate "attack" by the original artillery unit. The attacker, having already moved, suffers a -100% penalty for being hasty.

Land transports, when aboard a sea transport, seem to think they are aboard themselves, and will not move with the sea transport. At great expense, a bridge can be built like this. Likewise, an air unit that somehow becomes a carrier will land on itself with every move, ending its turn if it is not adjacent to a non-friendly unit. I believe the German version of SMAC/X has the Locusts of Chiron unit defined as a carrier.

Choppers, gravships, missiles, and needlejets with only one turn of fuel remaining will end their turns upon moving into a friendly base, unless a hostile unit is adjacent to it.

If you scrap all facilities of a type using the handy command, all bases, even those without that facility in the first place, are flagged as having already scrapped a facility this turn.

Curiosities or unavoidable bugs:

The effect of the Xenoempathy Dome seems to be that the owner can treat fungus tiles as roads, even to the extent of moving from fungus to road with 1/3 move, and road to fungus with 1/3 move. However, moving from an empty tile to a road costs whatever the underlying terrain costs, but moving from an empty tile to fungus costs 1/3 move.

Somewhat counter-intuitively, unit strengths in combat do not directly imply the odds that each will win a combat round (for one point of damage). The stronger unit's strength is effectively increased by the difference in strengths. Thus, a missile infantry attacking a silksteel sentinel in the open has a 8:4 odds in favor of winning each combat round.

Labs-increasing facilities stack additively, so that a Network Node and Research Hospital together double labs production.

Labs-increasing secret projects (Supercollider and Theory of Everything) stack multiplicatively, so that having both quadruples labs production, on top of facilities' effects.

Command Centers have maintenance equal to the highest reactor value discovered. Nothing else has variable maintenance.

A pactmate's needlejets can interfere with transports (CGN 24).

Wild mind worms in the open fight at reduced strength before 2115 (CGN 28). Wild mind worms, when attacking bases, fight at reduced strength until 2150.

Naval units can attack other naval units' attack values or defense values, by using long range fire or attacking normally. This makes purely defensive ships useless unless noncombat (CGN 35).

Some doubled doublings are triplings - nonlethal methods units under conditions of +3 Police quell 3 drones each (CGN 39). A tachyon field when combined with the appropriate defensive facility (perimeter defense, naval yard, or aero complex) triples a defending unit's strength.

The Skunkworks facility has the hidden bonus of allowing production to be reassigned within the same category (unit to unit or facility to facility) without loss of minerals (CGN 53). The Spartans cannot build Skunkworks because they already receive its listed benefit.

The Bulk Matter Transmitter, instead of adding 2 minerals to each base per turn, increases minerals at each base by 50%, additive with other facilities. This can cause massive, unexpected ecodamage.

Damage from an airdrop will never destroy a unit (CGN 3).

Echelon mirrors not in anyone's territory will not affect solar panels. Presumably, echelon mirrors in one player's territory will not affect adjacent solar panels in another player's territory.

Children's creches and morale interact in such a way that sometimes lower morale is better.

A base can never suffer more bureaucracy drones than it has population.

Talent-creating effects convert superdrones to regular drones before converting drones to workers and workers to talents.

Drone-reducing effects can convert superdrones directly to workers.

Prototyping a weapon, armor, or chassis will also effectively prototype all weapons, armors, or chassis of equal or lesser strength or speed (CGN 56). However, experimentation with the scenario editor shows that the game keeps track of whether each weapon, armor, or chassis has been directly prototyped.

Most SAM air units suffer a -50% penalty when attacking non-air units. Psi SAM air units suffer no penalty against non-air units. Psi SAM air units other than Locusts of Chiron, when attacking interceptors, attack with a psi value of 1, while the defending interceptor uses its weapon. Locusts of Chiron force the defending interceptor to use its psi of 1.

Two bases owned by different factions can work the same tile if the factions have not yet made contact.

Most facilities that add 50% to something, such as network nodes, round up. Mineral-increasing facilities round down.

Apparently, terraforming operations other than "raise terrain" and "lower terrain" can, in conjunction with global warming/cooling, cause immediate changes in terrain height.

Fungus in sea shelf tiles can "sink" and stop influencing production from those tiles, as a result of becoming ocean tiles. Other sea improvements do not sink.

Global warming/cooling, combined with the restriction that adjacent tiles cannot be more than one elevation category apart, and the retroactive enforcement of this rule, can silently "wash" endangered tiles of terraforming, units, and bases.

Disbanding most units in bases will add half the unit's mineral value to the current build, rounded down. Disbanding a native lifeform adds one mineral.

Native life units require no support while in fungus.

Some landmarks are destroyed by changes in elevation. These are: Monsoon Jungle, Garland Crater, Uranium Flats, Fossil Field Ridge, Manifold Nexus, Nessus Canyon, Mount Planet, Unity Wreckage, Pholus Ridge, and Geothermal Shallows.

Non-amphibious units normally cannot move between land and coastal sea bases. The presence of any transport (even a land transport) in the base bypasses this requirement. Additionally, a unit can move out of a sea base into a land tile occupied by a friendly unit without a transport, but units cannot move into coastal bases, occupied or unoccupied, without a transport or the amphibious ability.

Under some circumstances, discovering a "secrets" tech will not award the free tech until the following turn. This can happen as the result of cashing in an artifact or using another secrets tech to discover the secrets tech.

Wild spore launchers will sometimes attack each other.

Orbital defense pods do not have the listed 50% chance each to stop a Planet Buster, and seem to need to stop each PB twice.

The production of fungus tiles is not influenced by having a +2 Econ rating or by the Merchant Exchange project.

Under some conditions, the game turn will fail to advance for several turns.