These are unofficial changes ("house rules") that modify the Stargrunt II rules. These house rules are intended to fix holes in the rules, or bring more realism to the game.
The house rules fall into three categories: clarifications, modifications, and new rules. Clarifications are interpretations of existing SG2 rules that have not been verified by Jon Tuffley, the game's author (though many are commonly used by SG2 players). Modifications are changes to existing SG2 rules. New rules are in addition to those found in the rule book and are intended to "fill gaps".
Allocating Casualties - clarification of whether or not wounded/killed figures should be counted when allocating casualties.
Artillery - fixing the contradiction in the artillery rules, and adding a house rule for firing artillery at units hidden in terrain features.
Assault From In Position - rule for handling squads that want to charge into close assault while they are In Position.
Electronic Warfare - two methods that clarify the poorly written Electronic Warfare rules.
Multiple Support Weapons - rule for handling squads with multiple support weapons.
Split Fire at One Target - rule for allowing squads to split their fire so that the one squad can fire more than once per activation at the one target.
Vehicle Bail Out - clarification as to how vehicle bail outs work (passengers leave a vehicle after it's been disabled or destroyed).
Vehicle Loading/Unloading - a clarification of the vehicle loading/unloading rules.
Aerospace - modifications to the the rules for aircraft aborting their missions.
Morale - rules to make morale rolls less forgiving.
Quick-and-Dirty Fire Combat Option, Revised - A revised quick-and-dirty fire combat option, which fixes the problem of armour being less effective at long range.
Transfer Action Modifications - a change to the way Transfer Actions are conducted in order to reduce the "commander in the corner" problem.
Vehicle Bail Out - a modification to the bail out rules (clarified above).
Vehicle Loading/Unloading Range - a way of taking terrain into account when a vehicle loads.
Ambush Rules - rules for handling ambush scenarios.
Cross Training - rules for using weapons held by casualties, and for using captured weapons.
Fuel-Air Explosives (FAEs) - rules for thermobaric weapons.
Opportunity Fire and Overwatch - opportunity fire and overwatch rules to supplement the game's existing Reaction Fire rules.