Tactics have not yet been updated for the current 40K rules. I recommend you consult a forum such as Bolter & Chainsword as there is no forum on this website and this article is majorly out of date.
Having considered my force and the potential missions I must now consider potential foes. Surely Sun Tzu or someone said "Know thine enemy." Although I haven't played every army, I understand their basic strengths and weaknesses if not every individual piece of wargear. Also since marines are so popular and Chaos is basically marines with spikes if you were to optimize your army for one opponent you should choose marines. That said there are always some good Eldar players who make a run and the horde armies can throw you for a loop especially in certain missions as I learned in Calgary. So if you're out to win, plan to fight marines once or twice as well as a horde army and likely an army with more speed and mobility then you.
I actually have a lot of experience playing against marines and only two things scare me: multi mealtas and battle cannons. Anything that can kill multiple plague marines in a single shot and denies armor saves is to be feared. Even the mighty lascannon can only kill one plague marine. Thankfully the weapons I fear most have only 24" range but they're usually mounted on a vehicle of some sort which offsets this disadvantage. It's the lack of weaknesses and the ease to paint which leads to all the marine armies at Grand Tournaments.
I plan to set up normally as this is the normal opponent of Chaos and to follow the plans I laid out for the given missions. However since next to Chaos I know Loyalists the best I will be harshest in army selection I imagine.
You may think this is an unlikely army to face given the state of the miniature range and the rules, however I faced one in Calgary and I saw one or two more there. Plus it is an army most people don't plan for which is advantageous to the Sister's player. It is similar to marines in that there is a lot of power armoured troops. However they also have screens of lightly armoured troops. They lack long range Heavy Support but have ample access to the mighty multi mealta. I believe I scored the Sisters army I ran into higher then average because it is a rare and enjoyable army to play against.
I'm by no means an expert in fighting the Imperial Guard but I managed to massacre them in Calgary so I must be doing something right. It was very touch and go for a while though. Basically kill the tanks as quickly as possible and just suffer through the flashlights. Some people might want to rush into H2H and I admit I killed a few tanks that way with George and Slim but my Vancouver force is more shooty so I will advance but may stop a few inchs from the opposition and rapid fire. Guardsmen die so easily it is almost ridiculous, with my ample Heavy Support I'm less worried about the tanks. If I played every game in the tournament against the Guard I wouldn't complain.
With the recent release of the new Chaos Codex I expect more Chaos armies. Mind you I expected a lot of Tau and Necrons in Calgary but I never fought any of those armies. GW staff try to avoid you fighting your own army and the same army over and over so my dream of all Guard opponents will not come to be. In Calgary I fought the same army codex twice two times so I didn't get that much variety I hope for better in Vancouver.
Oh, how will I beat Chaos? Please we all know Nurgle is the best, and who knows Nurgle better then me? But seriously my army list isn't ridiculous and knowing the exact capeabilities of your enemy will only help. I'd actually welcome an all Chaos throw down especially against Tzeentch. Since Chaos has limited access to battle cannons and no multimealtas I fear loyalist armies more.
My success against the Orks is really all or nothing. I won big and lost big. Next to Chaos and Loyalists I know the Orks the best because it was actually my original army back in the Rogue Trader days. Alas the Orks I knew are no more. Now they are a slightly more shooty horde army. So anti tyranid tactics are in order, ie set up away from them and shoot them up. As Nurgle I like my chances in H2H the key is to maneuver and actually get the charge bonus. Orks have some trouble against tanks due to their low ballistic skill, so I will shoot the rocket boyz up early and just keep shooting with my Heavy Support. My army will advance to get into bolter range or at least to secure better defensive positions.
In my opinion burner boyz are the best orks, I mean they get a power weapon and a flamer and you can have scads of them. If I still played Orks I would OD on these guys of course this would probably have a detrimental effect on my army selection score should I be playing at a GT. When I assign a score to any future ork opponents I will reward variety of units and punish maxing out of juicy bits such as Burner Boyz.
There were a few Nid armies in Calgary but not that many. Somehow I managed to fight two Ork armies and that army seems to require as many models or more and may be the more difficult to paint. I'd like to play the Nids cause I've never played them in 3rd Edition and for that reason I may give them a slightly higher score in army selection. I actually was very good at fighting the Nids in 2nd Edition so I fancy my chances. Basically you set up deep in your deployment zone and keep shooting until the bugs are just about upon you then charge. The worst case scenario would be like my first game in Calgary, having to advance into the horde in order to accomplish the mission. I think the Nids will do well given the 18" deployment zones, I may not have enough guys to defeat a determined horde of Orks or Nids. Oh well I make no claims to having chosen the best army list possible.
Would you believe I've never faced these guys in 3rd Edition. I think once in some sort of mega battle I fought some. Basically this was the best army in 2nd Edition and still has the reputation of being the army for painters and the clever/cheesey player. That said Marines are the most popular and seem to win a lot of Grand Tournaments.
Although the rules have changed, the Aspect Warriors still fulfill the same tactical roles. So shoot the ones that want to get into H2H and assault the ones that specialise in shooting. However the 3rd Edition Eldar have so many snazzy toys that didn't have models for most of the 2nd Edition era. You don't see Eldar armies without Falcons anymore. Also the Vyper has a model too and they seem quite common. None the less the undisputed king of annoying Eldar vehicles is the Wraithlord. This was just a Dreadnought in 2nd Edition. Basically I plan to let the Eldar come to me, they have the speed and for all it's shootiness a lot of Eldar weapons are short range including the Wraithcannon. It might be amusing to try to kill the Wraithlord in H2H with my Lord and Retinue but a better tactic is to starve it of victims. If he foolishly sets it up on one flank I'm tempted to put my entire army on the other flank and watch it walk all game!
I may try some extreme deployments especially in some of the odder missions and/or against the more extreme opponents. Against the Eldar I think my three Heavy Support choices will do well because Eldar are brittle and if I deploy well I should get a round or two of shooting in relatively unmolested with my Heavy Support. After that it may be mopping up Guardians and the less vicious Eldar bits. The Eldar are a victim of their own reputation. All but the most naive player knows where the juicy bits are. That is why I think it is advantageous to play using a less popular army.
These guys seem to be less feared then the Craftworld Eldar. They are fast so in some missions they have a big advantage. They also have a tonne of assault weapons which is where it's at, in my opinion. At least prior to the latest rule change. None the less the Dark Eldar far from dominate at the GT level. And the one person I know who has a Dark Eldar army thinks his isn't overally effective. I've never actually played against them, but I know all about the waves of flying boats. Basically I'll treat them like the Nids. Set up deep in my deployment zone shoot the Dark Lances, charge them when the Dark Eldar get close. I usually avoid the cinematic clash of army generals but against the Dark Eldar I welcome it. They are the opposite of Nurgle fast but weak. I also think my lord can kill them instantly. Dark Eldar lords have retinues so it would make a cool fight, I'll be sure and take pictures.
I've actually played the Tau once, right when they came out. I think they are a great army list. They are shooty and shooty appears to be way to go at a GT. They have a lot of interesting units. Basically they may be the best and they paint up nicely. However they didn't dominate in Calgary but now all their units may be out. Since Tau want to shoot I want to advance. Owen seem to think their guns would kill Nurgle quickly, but that didn't happen in our previous game. I'm still going to be cautious against the Tau as they are a still largely unknown in a lot of ways to me. I have read the Codex though so I can tell the units apart.
The newest armies are always better, this benefits Chaos right now though so I best not complain much. I've fought these guys a bunch prior to Calgary and to quote Chris Bermann "this just in they're good". They are also shooty but they are tougher than the Tau. It can be argued that this army is tougher than Nurgle. Some of their big guns are down right nasty as is their wargear. And I know people fear the Pyramid. Despite all this I never lost to Thor's Necrons with my Diseased Sons. I'm not actually sure I have a more effective army list then in Calgary but I don't fear the Necrons. I plan to stay away from the Lord if he has the big stick. I don't anticipate shooting at the Pyramid at all. I'm just going to try to kill the regular guys and watch them warp out.
All things considered it is very possible that if you beat the Necrons in a Grand Tournament you'll massacre them which is the goal I guess. It maximizes your score at any rate. I managed to get two massacres in Calgary which caused me to go from the bottom to closer to the top in rankings. I hope to win my first game, hell all my games so as I can play against the better players. A massacre was only worth one point more then a solid victory (in Calgary) and in some missions it can be difficult to achieve so it is fairly impressive I managed to turn the trick twice considering how sub-optimal my army selection is. That's why I hope to do better in Vancouver or at least be more consistent. I need to paint so this is the end of my epic rambling until after the tournament.