The Archivus Tacticum Imperialis
Using the Blitz to your advantage can be difficult however. What you trade off in initial firepower, you regain in the element of surprise. There is one thing to remember however. No opponent is stupid. When I play against IG, I look at the troops in front of me, if they dont look like a full 2000 point army, or whatever size you are playing, then you can probably guess that your opponent is going to blitz you. It's never a surprise when I blitz someone, they know full well that it's coming. Thats where the key lies, in concealing your blitz.
One thing I noticed myself doing early on, was intentionally opening up a path between my units for the blitz to blaze through. This often prompted my opponents to gather weaponfire, and place heavy's on overwatch in an attempt to blast my tanks to bits. Which admittedly, worked. I learned that if you open up these paths in your formations, you practically beg the enemy to blast you. However, you do need somewhere to get your tanks through. This is where troop density comes in. Lets admit it, unless you are fighting lightly armored troops, lasguns aren't worth a damn. I use mine to provide secondary targets for the enemy, to keep firepower off my primary units. Cluster your troops together tightly. Not so tightly that one frag grenade will wipe them out, but so they are in clusters, not lines. Perhaps a 2x4 formation. This will leave more room for your tanks to get around.
Second, leave alot of holes open. If you leave maybe 3 or 4 holes open in your formation, the enemy's fire will have to be spread out more. Ideally he will either leave a hole in his coverage open, or at least thin it out enough. This also gives you a variety of options when bringing your tanks onto the field. You can flank the enemy, drive an armor column into him, or simply spread them out across the field. No single method is truly best here, it all depends on the conditions of your particular battle.
Now, lets assume you got your tanks in ok. Thats a start, the next thing you want to do is eliminate all major threats to your tanks. This doesn't nessecarily have to be done with the tanks, ideally you would have begun this with your enitre army. Start with any major threats, like dreadnaughts, and assault squads, then follow up onto other vehicles or heavy weapons. The fewer the destructive weapons your opponent has, the greater your riegn of terror as your tanks freely run down everything he has.
General use of tanks in combat:
I've played a number of games against the IG, where my opponent has treated his tanks like they were support for his main army. While yes, they do come from the support section of the army list, dont think of them like this. They are what makes you go. The imperial guard are nothing more than organized orks without thier tanks. They can do nothing but run around and piss on people with thier lasguns. Not very effective at all in a S4 T4 world of 40k. The tank is what gets the job done. When you roll off a battery of heavy firepower, you are causing casualties. When you roll ten dice for lasguns and fail to even wound one marine, you are creating a distraction. Your tanks are the key to your winning the game, use the imperial guardsmen to shield your tanks. Rush them into completely outmatched close combat to hold back potential tank killers, until you can get your big guns aimed in on the frey. And most of all remember this, anything that isn't the emperor, is cannon fodder. I never think twice about firing at that single guardsman surrounded by genestealers. He is gonna die anyhow, make his death useful, hit him with a demolisher cannon. Praise to the emperor, for he has died valiantly in battle, grouping your opponent up for a nice big blast radius kill.
Players in general have this incredible fear of armor. Tanks become a divine target for every nut with a krak grenade. If you field a single tank, and have a smart opponent, you will find it in pieces the first opportunity he gets. If you field two tanks, now he has half the power to bear on each tank, increasing the survivability of both. Now take this to the extereme, field as many tanks as you can. Your opponent will be overwhelmed, and you will have an awesome battery of fire to immolate him turn by turn.
I named this move after the warmaster who most likely used it in combat. The move is simple really. In your first turn, don't set anything up. Buy chimeras for all of your troops, and buy an abundance of fast moving killer tanks like the hellhound. Make sure you spend points on a basillisk or two, and get a few leman russ's to even things out. Maybe even a Sentinel or two would be nice. Now, when the second turn rolls around, blitz out your fast moving destruction tanks, and cover thier atttack with barrages from the basilisks off the board. Third turn, follow in with your chimeras, and unload your enitre army onto thier side of the board. If everything is planned out correctly, you should be able to unload all your troops on turn four, and wreck havok. Ideally this move would be best suited for longer games, perhaps in the 5-6 turn range, giving your troops alot of time to make a mess of things back there. Charge into close combat, overwhelm him, even unload heavy weapons back there and just lay into him. Let your tanks clean up the mess.
When blitzing, alot of opponents assume you are going to bring everything on at once. Don't. Hold back a tank or two for a surprise in the third or fourth turn sending them where they are needed most. When the initial shock of your first blitz is over, your opponent will assume this is all you have to offer, and plan accordingly. The second surprise is what nails it home. Suddenly two extra tanks show up that he was not prepared for, now he needs a new plan to deal with it.
This is my favorite move. Bring your tanks on in a single line, down the side of the board. The range of your various guns should be able to really lay into everything on that side of the board, slowing to combat speed, you can come round your enemy, and plow through his deployment zone, blasting him out from behind cover. He will either have to stand and fight your mass of tanks, or run out into the open where your guardsmen on the other side can pick him off. One thing that helps alot, is to have a hellhound lead this column. The fear factor, along with the ability to fry any large troop concentrations direcly in front of you are very very helpful.
The pinch is a simplistic maneuver, but can be very deadly if executed properly. Once again, this maneuver relies on a high speed two stage blitz. The first blitz brings two groups of tanks from either side of the board, arcing towards the center. The idea being as you pass by the front line, blast away at it with turrets and sponsoons. On the next turn, bring a fast moving strike force, preferrably hellhounds, chimeras etc, up the center of the field, and hit the enemy right up the middle. Cross the two flanks at the middle and continue arcing across the battlefield, charghing into the lines, while your center spreads outwards across the back lines. Variations on this maneuver could include forgoing the center punch, and or one of the flanks.
Generally I don't use this maneuver, as it's very subject to mass immolation. But in some circumstances it works well. Basically, in the first turn, line your troops up pretty much all across the front line, as far to the front of the deployment zone as possible. Immediately run all troops forward, this will place you 20 inches onto the field. Second turn, bring tanks on, lined up behind the infantry, preferrably at slow or combat speed. Don't overrun your infantry. Keep running the troops ahead, placing you 28" onto the board, with your tanks trailing them by about 5 inches. This maneuver works best if any heavy weapons groups you have in the back are using mortars to fire over your troops, otherwise most of your LOS is blocked by the formation. In the third turn, walk your troops, putting them at 32" on the field, they can now open fire, hopefully taking out some enemy troops, and the whole time your tanks are protected by the screen. The problem with this maneuver is that it is very vulnerable to massed firepower, and or charges from the enemy. If an enemy assault unit charges your front line, don't hesitate to blast your own troops, or run them all down, it will most likely save your skin. Remember, 32" onto the board means most of your enemy is going to be in short range for your lasguns, you might actually hit someone. Continue walking into the fourth turn, avoid close combat if possible. Close combat simply means you will need to annihilate your own troops in order to kill the enemy.
However thats where it stops. You can't play them like orks, because quite simply they aren't orks. They can however, use similar tactics.
When attempting to use your Imperial Guard without the benefit of tanks there are three main strategies you can use.
I'm not a big fan of the third option, and it's pretty obvious, this is how you probably play now. So I won't bore you with that plan, instead I'll speak about the other two styles of IG armies.
Buy cheap troops, and give them cheap stuff. Don't waste points. If you need to, buy inexpensive heavy weapons, like heavy bolters, and the occasional las cannon just in case. Ideally, you should forgo all heavy weapons at all, and load up on melta guns. You take a risk here, but you can afford more troops this way. Command squads are the key here. Command squads full of melta guns, one squad of them for every three tactical squads, means you can field infantry forces 35 strong, with 8 melta guns between them (assume the lieutenant takes one) at a cost of 402 points per battle squad. In a 2000 point game, this gives you 5 of these groups, if you pull a melta gun or two out somewhere. Thats 175 troops, 39 with melta guns. Tell me you wouldn't fear that marching across the field towards you. The idea here being, that you completely overwhelm your opponent, and literally just swarm over his position. For added effect, run and charge the whole army into close combat. against marines you will probably be fighting 5:1 odds, and thats pretty damn good odds even against marines.
Now obviously not everyone can afford to have a 175 troop IG army at thier disposal. Just imagine if you wanted to play 3000 points. It would become rediculously expensive. You can even this number down more by spending money on vetran upgrades for all your squads, heavy weapons teams, Storm troopers, psykers, etc etc etc. You still have quite a formidable force left over, and its a bit more rounded. The tactics remain the same though. When I'm playing light on vehicles, or with none at all, I line my troops up, and walk across the field, firing like mad.
This is the tactic I usually use. Generally I just stock up on as many support squads as I have at my miniature disposal, which is currently 6. This excludes my three command squads which are armed with heavy weapons too. I have a desert army, which I am very fond of, because it contains two full squads of autocannons. Autocannons are cheap, and VERY effective. You get a single sustained fire die, the ability to reshoot missed shots with the vetran skill, and S8 hits if you hit anything. It tends to make quick work of marines and anything else you encounter.
Heavy bolters are also dirt cheap heavy weapons. You can field squads and squads of these at practically no cost to yourself. And we all know how wonderful massive amounts of heavy bolter fire can be.
To round it off, I usually scatter a few rocket launchers and lascannons around. This helps take care of any tanks or heavily armored opponents that might be lurking about. And in leiu of that, you can allways devestate some poor gimp with a lascannon shot to the head.
If you aren't rich, and I'm sure if you play 40k, you aren't. You need to stock up on vetran abilities. They will add points to your army so you can field a full battle's worth of heavy weapons. And they come in handy too. Lascannons firing twice a turn are great for wiping pesky dreadnaughts off the field of battle. If need be, steal the weapons teams off your tactical squads and put them together to make another team. Spread your troops all across the back of the field, preferrably in heavy cover, and just shoot like there is no tomorrow.
A note on missile launchers. I hate missile launchers. I never field them unless I'm stuck doing so. Why? Simple.. they explode. Imperial guard miss ALOT. Especially considering they don't have the luxury of targeters. When you miss alot, eventually, you are gonna roll a hit-misfire, and blow yourself to bits. Nothing is more annoying than this. Other weapons may jam up all the time, thats fine, if you have enough, you shouldn't be affected by this. When I play I usually have about 3 weapons jammed at any one point in the game. I plan for this, I know its going to occur. But they unjam, dead troops don't come back to life. And if your missile launcher has a slick crew, it's pretty much begging to die. So if you do field one, keep it away from your other troops, don't kill anyone else with it, and NEVER fire it near your own tanks, troops, etc. It will undoubtably miss and blow your tanks up.
To sum things up, Like I said before, I'm not a general. But I believe these tactics are sound, and will lead you to victory if you use them well.