Models and Base Sizes:
Language about using the proper base is less strict.

Measuring Distances:
Measure distances at any time.

Zero-Level Characteristics:
If S or T (and obviously W) reduced to zero, the model is removed.

Dice/Randomizing:
New guidance on how to randomize

Basic Vs. Advanced rules:
In short, more specific rule has precedence

The Spirit of the Game:
Clearly spells out not to follow the rules

Models in the way:
Change to enemy models instead of another model. Move through own models now?

Moving:
Determine for individual models if they moved or not. Heavy gunner can stay still and the rest of the squad can move.

The Wound Pool:
Finally gave a name to something we all do

Allocate Wounds:
Closest first if homogenous, allocate and resolve one at a time from closest if heterogenous. No more multi-wound/different wargear allocation shenanigans. In non-directional (Terror from the Deep), randomize who gets wounds.

If you have shots with multiple AP values, the shooter pics which group/category to resolve first.

Out of range doesn't prevent wounds (if were in range at the beginning), but out of sight does.

Instant Death:
Removed the language about war gear boosting T. Bikes, et al, get the TWolf Mount bonus.

Look Out, Sir:
Put Character wound on another within 6" on 4+ (ICs on a 2+)

Cover Saves:
Now 25% of the model. Intervening units are 5+ cover save.

Go to Ground:
You can Snap Shot (BS1) when Gone to Ground, and shoot Overwatch.

Cover Chart:
Forests and area terrain change to 5+

Focus Fire:
Shoot only people in specified cover

Overwatch:
Shoot per Snap Shot rules as soon as charge is declared, before rolling charge distance and before moving chargers.

Charging:
2D6 for charge distance. 3D6 pick 2 lowest for charging through difficult terrain.

Initiative Pile-In:
At models' I: if not in base to base, move 3". You can fight after Initiative Pile-In, right?

Rolling to Hit/Wound:
Each model trying to hit compares his WS against the majority WS of engaged enemy models. Same for rolling to Wound-- majority of enemy toughness.

Close Combat Wounds:
Closest first, just like shooting. First to models in base to base, attacker picks which goes on which. Once all those are dead, then allocate to next closest.

Our Weapons Are Useless:
Can flee if can't hurt enemy; auto-fail Morale test. Fearless don't get to do this.

End of Combat Pile-In:
3" now.

Charging Multiple Units:
Called a Disordered Charge and you don't get the +1 charge bonus. If you are engage with multiple units, a model can split attacks.

Falling Back:
Can only Snap Fire while falling back. No more 6" enemies to prevent regrouping. You can normally down to 25% alive. Under 25% only regroup on Insane Heroism. If unit has an IC, it can always regroup on normal Ld test.

Acute Senses: re-roll which table edge when Outflanking
ATSKNF: also Immune to Fear (duh)
Fleet: re-roll one or more die when Run or charge (not all dice, can pick just one)
Furious Charge: Only +1 S
Gets Hot!: On a 1 and then another roll of 1-3, vehicle takes glancing hit
Infiltrators: Can not charge first turn
Move Through Cover: auto-pass Dangerous Terrain test, not effect on Charge roll or Impact test
POMS: Can't use when Flat Out or Smoked
Preferred Enemy: Re-roll hits and wound rolls of 1
Rage: +2 A when charging
Rending: AP2, so gets a damage table bonus on vehicles
Scout: It is worded differently, but I think the same?
Skilled Rider: auto pass Dangerous Terrain tests, +1 Jink save
Slow and Purposeful: Can't Overwatch
Sniper: to hit of 6 = Precision Shot
Swarms: trade Stealth for ignoring difficult terrain and now can provide intervening unit cover
Tank Hunters: re-roll Armor penetration roll and can choose to re-roll a glance

New Special Rules to the BRB: Adamantium Will, Armourbane, Blind, Brotherhood of Psykers/Sorcerers, Bulky, Concussive, Crusade, Daemon, Fear, Fleshbane, Force, Hammer of Wrath, Hatred, Haywire, Interceptor, Ignores Cover, It Will Not Die, Jink, Monster Hunter, Missile Lock, Psychic Pilot, Rampage, Shred, Shrouded, Skyfire, Smash, Soul Blaze, Specialist Weapon, Split Fire, Strafing Run, Strikedown, Supersonic, Torrent, Unwieldy, Vector Dancer, Vector Strike, Zealot.

Bikes: Only take dangerous when charging across Aegis or barricade. Eldar Jetbikes move 2D6 in the assault phase and can turbo boost 36". Get Hammer of Wrath and Jink.

Artillery: Guns now have a profile, always use Gun's Toughness when shooting at Artillery

Jump and Jet Pack split types. Beasts and Cavalry also split.

Jump: using Jump Packs to charge lets you re-roll charge distance and gains Hammer of Wrath. Jump Units are Bulky.

Jet Pack: Get 2D6 Assault Phase move

Beasts: Ignore difficult terrain, even when charging, gain Move Through Cover.

Cavalry: Get Hammer of Wrath. Ignore difficult terrain, even when charging, but take Dangerous Terrain test.

MC: Fear, Hammer of Wrath, Move Through Cover, Relentless and Smash.

A whole page of new stuff for Flying Monstrous Creatures.

Can fire Heavy Weapons if moved using Snap Shot. Squad can move, but if model with Heavy didn't move, he fires with normal BS.

Dual pistols can fire both in shooting.

Rapid Fire:
Can move and shoot 1 at full distance

New Weapon Type: Salvo

Template weapons can fire Overwatch, but not Snap Shots. If fired in Overwatch, inflicts D3 hits.

Close Combat weapons now have AP. Lots new variations.

Assault Grenades:
Can be used in Shooting with 8" range

Plasma Grenades:
Same as Assault, but better shooting profile and can also be used against Vehicles and MCs in the Assault Phase.

Defensive Grenades:
Get Stealth if within 8"

Krak:
Can be used for Shooting and in assault as weapon.

Characters:
On a 6 to hit when shooting, you can pick target model. Can't with Snap Shot, shots that scatter or don't roll to hit.

On a 6 to hit in assault, pick target of engaged models.

Challenges and Glorious Intervention-- two pages of new rules here.

Psykers:
Get one Warp Charge per Mastery Level each turn. Use the Warp Charge to use powers. No saves from Perils. Must have line of sight to target, if in a vehicle you can only target self, embarked unit or the vehicle. Anyone can deny the witch on a roll of a 6. Did Psychic hoods just become 6" range?