Second Sphere Rules

Combat Rules

Space Combat Resolution

Vehicle to Vehicle Combat (guns)

1) An attack on a vehicle rolls a D20, attempting to defeat ([DefAgility - OffAgility] + [Evasion - Accuracy]). If the D20 roll exceeds this number, the attack has hit.

1a) Mission type 'Intercept' allows the replacement of OffAgility with OffSpeed.

All Vehicles/Craft are deployed on 'Missions'. They determine what the group is doing and provide various bonuses.

2) On a successful hit the attacker rolls another D20, attempting to defeat (Armor - Penetration). If the D20 roll exceeds this number, the craft takes the weapon damage (normally 1).

Agility is, not surprisingly, important for superiority craft. Somewhat different rules apply for guided missiles.

Ship to Ship Combat

1) An attack on a ship rolls a D20, attempting to defeat ([Armor - Penetration] + [Evasion - Accuracy]). If the D20 roll exceeds this number, the attack has hit.

All warships are assumed to have proper electronic warfare and sensor suites; at 'gun range', long-range sensors become meaningless against these large targets.

2) If the weapon is an E-type (energy) weapon, on a successful hit, roll a D20 vs the ship's energy absorbtion threshold. On a success, all damage from the attack is directly moved to the Energy Sink pool. Any excess, any attacks that fail this roll and all Kinetic attacks go to step 3.

Modern warships include substantial protections against energy weapons. Kinetic kill weapons avoid them but are less accurate.

3) On a successful hit the attacker rolls another D20, attempting to defeat (Structure - Strength). If the D20 roll exceeds this number, the ship takes the weapon damage.

Warships are substantially larger and thus more resilient than any craft. Weapons that would blow through meters of armor might merely poke an inconsequential hole in a two hundred meter cruiser. Anti-ship weapons require strength on top of armor-piercing ability.

Guns are one of the ways ships blow each other up. Unlike anti-ship missiles, guns do not run out of ammo in the middle of a fight. Additionally, they can be used defensively, against craft or missiles.

Vehicle to Ship combat

1) As per Ship to Ship combat, but OffAgility is added to Accuracy.

2) Unchanged

3) Craft at Point-blank range can effectively strike at weak points (airlocks, turret rings, etc), adding OffAgility to Strength. **May need consideration**

The best way for craft to destroy ships is get right up close and shoot them in the important bits. 22nd century dive bombing. Heavy anti-ship missiles can also be used, but anything short of a bomber can't carry more than one or two.

Ship to Vehicle combat

1) An attack on a vehicle rolls a D20, attempting to defeat ([DefAgility + ECM - Sensors] + [Evasion - Accuracy]). If the D20 roll exceeds this number, the attack has hit.

Craft have much smaller sensor cross-sections than warships and are much easier to protect via decoys. Thus sensors and ECM become much more important.

2) On a successful hit the attacker rolls another D20, attempting to defeat (Armor - Penetration). If the D20 roll exceeds this number, the craft takes the weapon damage.

Ground Combat Resolution

Ground combat functions broadly similarly to space combat, though with some key changes. The concepts will be explained below.

Formation Scaling

As opposed to space combat where almost all engagements occur between a relative handful of ships and their carried craft, ground combat can range from a few squads trying to capture a key objectives to armies of tens of thousands of soldiers and robots clashing for control of a world. Thus Sphere functions on a progressive scaling system of both number of individual soldiers/vehicles one 'unit' represents and the relative time involved; a squad operation can be over in a day, whereas a single combat phase for a division-level conflict might be weeks of time.

Squad (10): Generally this is where explorers and special operation grounds are. Ground vehicles are treated on the individual level.

Company (100): The lowest level of 'military' operations. Typical for frontier operations. Companies tend to be homogeneous to one type of infantry or vehicle.

Battalion (1000): Battalion level operations are the norm for hot wars. At this level almost all units have a certain ability to 'multitask'.

Division (10,000): Generally only seen on particularly large ground conflicts, such as Kanon, New Mercia and Sarreva.

Terrain

Unlike (most) space, land is not an empty expanse of nothing. Even the least rugged terrain will provide opportunities for concealment and misdirection. Thus the more difficult terrain provides a defensive bonus, as well as decreasing mobility.

Barren: Particularly flat and featureless land, like the Iraqi desert or some cultivated land (which is not 'barren' in any sense!)

Open: Most habitable 'outdoors' that features mixtures of open and wooded areas, typically with minor topographic shifts - or the offworld equivalent.

Difficult: This is substantially more difficult for armored units and generally represents fully wooded areas and hills.

Very Difficult: This is truly rugged and painful territory, such as the triple canopied rainforests of Kanon or the wooded mountains of British Columbia.

Urban: A subset of Difficult terrain, Urban is built up land. The network of roads allow for rapid transit by vehicle but the various low buildings and houses provide ample concealment for troops and tanks alike.

Heavy Urban: Very Difficult, now with concrete. Street networks continue to provide excellent mobility for vehicles, but heavily-built buildings like highrise apartments and industrial complexes provide immense opportunities for defense and concealment.