Hope the HTML comes through okay...
Here's an attempt at compiling together ALL the combat possibilities in the game in one place. I think I've personally tested every scenario here, although I may have missed one or two. This is all in SMAC 4.0; I do not have SMAX so SMAX-only features like Dissociative Wave are missing.
Hope it helps somebody, and hope it's accurate. Have at it! Any corrections/info welcome.
| Basic Rules |
| The "defender" is selected from the defending stack as the unit with the best chance to win the combat.Land on transport cannot defend |
| Psi Combat occurs if attacker has Psi Attack or defender has Psi Defense.* All native units have both |
| Probe Combat occurs if attacker is any Probe Team and defending square contains any Probe Team.* Probe combat is never Psi |
| "Sea Gun" is Attack>0 and no Psi Attack or Psi Defense.* All Sea Gun units have artillery capability. |
| Always MULTIPLY all factors.* Sole exception is base defenses. |
| Combat Scenarios |
| Requirements for the effect | Effect | Applies to | Note |
| Circumstance | Attacker | Defender | Defender's square | | Norm | Arty | Psi | Probe | |
| Normal Combat | Land non-artillery | Land any | | | Y | | Y | Y | |
| Bombardment | Land artillery | Land; no arty in stack | | One round, all damaged | | Y | | | |
| Bombardment | Land artillery | Sea Non-Gun | | One round, all damaged | | Y | | | Including land units on transport |
| Artillery Duel | Land artillery | Land artillery | | To death; defender uses A | | Y | | | |
| Artillery Exchange | Land artillery | Sea Gun | | Each fires one round | | Y | | | |
| Normal Combat | Sea | Any | Sea (including sea base) | | Y | | Y | Y | Naval Yard applies; Perim doesn't |
| Bombardment | Sea invoking Fire action | Land; no arty in stack | | One round, all damaged | | Y | | | |
| Artillery Exchange | Sea invoking Fire action | Land artillery | | Each fires one round | | Y | | | |
| Artillery Duel | Sea invoking Fire action | Sea Gun | | To death; defender uses A | | Y | | | |
| Bombardment | Sea invoking Fire action | Sea Non-gun | | One round, all damaged | | Y | | | Including land units on transport |
| Normal Combat | Air | Anything not SAM Air unit | | | Y | | Y | | |
| Intercept | Air | SAM Air unit | | Defender uses Attack value | | ?* | Y* | | Whenever interceptor defending (not just scramble) |
| Scramble Protection | Air | Anything not SAM Air unit | SAM Air in (air)base within 2sq | No Combat | Y | | Y | | Defender's SAM unit moves; use previous line |
| Sea attacking unit on land square (incl. Sea in port) is always Fire action.* Sea attacking sea, or land in sea base, can choose normal or artillery fire |
| Damage limits apply to arty Bombardment and Exchange: 50% maximum for units in bunker/base, 99% for other units on land |
| *I think the game treats Intercept combat as Artillery Duel. You do not get Confirm Odds screen. Air vs Air, Sensors, Base don't apply. |
| *BUG: If a defending interceptor has Psi Attack, Psi combat occurs, but the attacker uses its Weapon value vs Defender's Psi=3! |
| Air units in base/airbase, and Copters/Missiles outside base/airbase, can be attacked as if they were land |
| SAM air units (including Copters but not Missiles) always defend vs air as Interceptors, but cannot scramble if outside (air)base |
| Special Ability Required |
| Amphibious Pods | Land on transport | | Land square | No Combat if attacker lacks | Y | | Y | Y | CAN capture empty base without Pods |
| Amphibious Pods | Land anywhere (land or transport) | | Sea Base | No Combat if attacker lacks | Y | | Y | Y | CANNOT capture empty base without Pods |
| Air Superiority (SAM) | | Airborne Aircraft | Not Base/Airbase (Airborne) | No Combat if attacker lacks | Y | | Y | Y | SAM land/sea can attack air over sea/land |
| Base and Terrain |
| Base | Without Blink Displacer | | Base | Base Dx1.25 | Y | | Y | | Use only the highest Base value |
| Perimeter Defense | Land without Blink | | Base with PD | Base Dx2 | Y | | | | |
| Naval Yard | Sea without Blink | Sea | Base with NY | Base Dx2 | Y | | | | |
| Aerospace Complex | Air without Blink | | Base with AC | Base Dx2 | Y | | | | |
| Tachyon Field | Any without Blink | | Base with TF | Base Dx2 or Base Dx3 | Y | | | | If PD, NY, or AC applies, gives Base Dx3 |
| Terrain | Land | Land | Rocky or Forest, not base | Dx1.5 | Y | | | | |
| Fungus Special | Native or has Pholus Mutagen | | Fungus | Ax1.5 | Y | | Y | | Applies to all defenders (even air) and Sea Fungus |
| Fungus Terrain | Land, Not Native and lacks Pholus | Land | Fungus | Dx1.5 | Y | | | | DOESN'T apply to Sea Fungus |
| Bunker | Land without Blink | Land | Bunker | Dx1.5 | Y | | | | |
| Situational Modifiers |
| Sensor | | | In def territory within 2sq | Dx1.25 | Y | | Y | | |
| Infantry vs Base | Land unit, Chassis move =1 | | Base | Ax1.25 | Y | | | | |
| Mobile in open | Land unit, Chassis move >1 | | Flat/Rolling;No Forest/Base | Ax1.25 | Y | | | | Applies even vs Bunker and ECM |
| In Port | Land or Air | Sea unit | Base (even sea!) | Ax2 | Y | | | | |
| Non-Combat Unit | | Attack=0;Armor=1 | | Dx0.5 | Y | | | | |
| Hasty | Non-native land w/fractional move | | | AxFraction (0.66/0.33) | Y | Y | * | Y | Applies to Psi-weapon units but not natives |
| Fanaticism | Faction with bonus (Miriam) | | | Ax1.25 | Y | | | | |
| Elevation | | | | x1 + 0.25*level | | Y | | | Higher unit in arty duel - Including vs. sea |
| Land Based Guns | | | | x1.5 | | Y | | | For land unit if vs. sea unit |
| Open Ground | Bombarding | | Flat/Rolling;No Forest/Base | Dx1.5 | | * | | | Applies ONLY during arty Bombard (not Exchange) |
| Planet SE rating | | | | x1 + 0.10*Planet | | | Y | | |
| Dream Twister | Faction possesses Dream Twister | | | Ax1.5 | | | Y | | |
| Neural Amplifier | Faction possesses Neural Amp | | | Dx1.5 | | | Y | | |
| Special Abilities |
| Airdrop | Has airdropped this turn | | | Ax0.5 | Y | Y | | * | Probes can't move after drop; psi units can't drop |
| Comm Jammer | Land unit, Chassis move >1 | Has ECM | | Dx1.5 | Y | | | | |
| Ground Strike | Air with SAM | Not Air Unit | | Ax0.5 | Y | | | | |
| Air-to-Air | Air with SAM | Any Air (incl. Copter) | Not Base/airbase | Ax2 | Y | | | | Does not apply to Intercept combat |
| AAA Tracking | Air | Land or Sea with AAA | | Dx2 | Y | | | | |
| Nerve Gas | Has Nerve Gas special | | | Ax1.5 | Y | | | | Optional, Atrocity, Win vs base halves pop |
| Empath Song | Has Empath special | | | Ax1.5 | | | Y | | |
| Hypnotic Trance | | Has Trance special | | Dx1.5 | | | Y | | |
| Other |
| Morale | | | | x0.75 + 0.125*level | Y | Y | Y | Y | |
| Hit Points (Reactor) | | | | | Y | Y | | Y | |
| Collateral Damage | Land, wins combat | Land, loses combat | Not Base or Bunker | Damage all in defend stack | Y | | Y | | If defender was native, all native in stack destroyed |
| BUG: Game erroneously considers Reactor type when displaying odds for Psi Combat |
