Combat is different. Period. Attempts have been made to emulate the original combat mechanics as close as possible, but to expect identical results is unrealistic.

PVCR Program: The VCR program must be able to re-play battles according to the same algorithm as the host program. Therefore, to play PHost combat, the VCR program must be replaced by one which knows the PHost combat code. The HOST combat algorithm was not publicly known when PHost was initially written, so PHost simply had to invent its own. For instructions how to install PVCR, see First time with PHost.

Tunable Knobs & Alternate Combat: The PHost VCR program is configurable. Alternate Combat provides a rather different weapon hit model.

Combat Order: Combat order is slightly different than in HOST. The complete rules are documented in the Order of Battle section. The main differences are that

  • in HOST, planets always fight after ships (there are two phases of combat: ship/ship and ship/planet), whereas they are part of the normal battle order in PHost
  • PHost distinguishes between aggressor and opponent, HOST does not
  • PHost since v3.4b respects battle order for intercept attack.
  • in HOST, ships must decloak at once when they reach the DamageLevelForCloakFail. In PHost up to version 4.0i, they would stay cloaked for the whole combat phase, and could even supply-repair to stay cloaked.

Planets: In PHost, planets can capture ships by killing off their crew. In HOST, planets can only destroy ships. This aspect of the game design was actually intended for inclusion in the original HOST program. As it would have required patching vcr.exe and distributing a new copy to all players, this change was judged too great to implement in HOST.

Planets that take damage in combat will remember that damage for the next fight. In HOST, they'll continue with reduced defense, but without damage.

Lizards: In HOST, Lizard ships can be damaged up to 150%. In PHost, every ship which ends a turn with 100% damage or more is destroyed. It is still allowed to reach 150% damage during movement through mines, or during combat.

It can be argued that HOST's behavior is a bug (what does it mean to have more than 100% damage?). In any case, PHost compensates for this difference by making the damage-limited ship speed and shield level formulas relative to 150% damage rather than 100% (see the Formulas page for more details). This gives the Lizard player a slight advantage to compensate for the disadvantage of not having ships with greater than 100% damage survive.

The same reasoning holds for planets. Lizard planets are allowed to suffer up to 150% damage in battle but will explode (be conquered) if they end a battle with more than 100% damage.

Damaged Ships: Since PHost supports ships with more than 10 weapons of a type, the damage limit formulas have been changed to support that. In HOST, a ship with 50% damage can use at most 5 weapons. In PHost, a ship with 50% damage can use half of its maximum set of weapons.