Combat Overview: These steps remain basically the same to 1st Ed. Steps two and three have now been combined, and there is a new step two. This is new flow for combat.
Step 1: Surprise - This step sees a massive change. No longer does a surprised character lose his first turn. Instead now all characters have four action points (AP) per turn. Characters that are not surprised on the first turn gain an extra two AP that can be used as reactions. This is a welcome change so that at least a surprised character can try to find cover in the first round.
Step 2: Set the Scene - This is basically the GM detailing what is happening in the encounter. This should at least detail where the characters are at and describe the combatants that they are to face (if they can see them). This would also be drawing out a map and placing models if that is how you play.
Step 3: Determine Initiative - This is still done by rolling 1d10 and adding your agility bonus.
Step 4: Combatants Take Turns - These phase is actually broken down now and goes like this.
Condition triggers - this is any ongoing effects in place from last round are taken care of. Poison, Hallucinogenic effect, etc.
Clear Action Points - Remove any that you did not use in the prior turn.
Receive Action Points - Receive four AP that can be used this turn.
Perform Actions - Use your AP in anyway you want.
Combatants Actions - other combatants may use free actions or reactions to what you are doing.
End of Turn
Maintain Action Points - If you did not use all four AP, then you keep them to use a reaction in another character or combatant's turn.
Condition Timers - Count down on any timers that might be in play, once an effect has lost its last timer than remove in from the game at that time.
Actions: You now have the following differant action catagory types.
Attack Actions
Movement Actions
Utility Actions
Reactions
Extended Actions
Free Actions
These are basically the same as before except the use of AP instead of Half/Full Actions. This allows for you character to do many more things in a round of combat as most things are 1 AP.
The Attack: The attack has changed a little bit as well.
Step 1: Choose Attack - this is to decide your action for attack, weapon, rate of attack (RoA) and the characteristic.
This is a little differant as some attack actions can use another characteristic besides WS or BS I haven't noticed any outside of psychic powers at this point. The other interesting thing is that all weapons now have a RoA. This is by taking your Rate of Fire (RoF) and multiplying it by how many AP you use to attack with. Even melee weapons have a RoF now. This is usually one or by taking your Agility Bonus and subtracting a modifier. This determines how many times you can hit after the first if you have many degrees of success. Also, this is really interesting addition to combat and gives a awesome advantage to being fast in combat besides determining initiative only.
Step 2: Choose your Target - This is effected by range and sight/targeting.
Step 3: Make the Attack - This is your 1d100 test against the used characteristic. Hopefully you roll low :)
Evade Reactions can be used at this point by the oppponent.
Step 4: Determine Location - Instead of reversing the 1d100 role like before, you just use the tens digit from your attack role to dedtermine location. This also gives a bigger advantage to rolling low.
Step 5: Attack Results - This is the damge from the weapon minus the defence value of the location and the targets toughness. If the damage exceeds the defence + toughness then the model takes a wound and must consult the wound chart for location and amount of wounds suffered and apply the injury to the character. If the character has been hit in the same location multiple times and taken wounds from that , there are modifiers to increase the level of injury. This is completely differant from before as these charts were only used when a character had taken damage beyond his total number of wounds... Ouch!
This is much more brutal, but thinks make much more sense. I really like how this has changed the injuries and makes you want to use cover and be cautious instead of running up to get into melee...
Vehicles: There are now vehicles to use, and you can fight combat with them. The fundamentals have not changed so Im not going into them. The main thing is that vehicles have firing arcs and are not as manoeurable as a normal man/woman.