Editing Warhammer 40,000/7th Edition Tactics/Space Marines (section)

===Troops===
*'''Tactical Squad''' - Your bread-and-butter scoring units. These guys don't excel at anything but are decent at everything. Unfortunately, their balance tends to be their downfall as most other basic troops tend to be better at everything than they are (see: Grey Hunters), and they're a tad expensive when fully kitted out. Keep them at a distance if possible, but remember to make effective use of your Rapid Fire range. Great for camping objectives, as their durability is their best selling point. Always take Dedicated Transports with your Tacs, even if they're camping an objective. Metal Boxes make excellent walls and mobile shields for your troops, plus if Tacticals are inside and the Rhino gets charged they can Overwatch from the hatch. These fellas make up the bulk of almost every Space Marines Decurion, so you should get used to them and their capabilities.
**Important side note, if you plan to assault with these men remember they all have Bolt Pistols, meaning you can unleash 10 bolt shots (or 9 bolts and a krak grenade) before your charge. Generally, though, you shouldn't assault with Tacticals because even if the enemy unit is squishy, you could just Rapid Fire your boltguns instead (unless you want to tie up a squishy enemy that has good shooting but is terrible in close combat or if you want to hide your tacticals on a CC to avoid being shot up from other stuff or you want to deny an imminent Raging/Furious charge of a tough unit). So ''if'' you ''do'' charge, always remember your pistols/grenades/assault weapons.
**If you manage to run away and your enemy catches you, your Marines aren't auto-killed but continue the fight instead.  Remember this! Next thing to remember, if your enemy does not catch you and you break out in their close-combat phase, on your next turn which comes right up your Marines are auto-rallied. They also count as '''not having moved'''. In other words, rocket launcher (or 5 Grav-Cannon shots) in the face, or 6" move.
**Loadouts for Tacs usually consist of special weapon and matching combi-weapon (i.e. plasma gun and combi-plasma). If you have a 10-man squad, consider Combat Squadding, giving one 5-man group the combi-weapon and special weapon, and giving the other 5 men a heavy weapon to sit on an objective with. Your choice of Dedicated Transport, what your army needs (anti-tank, anti-horde, anti-heavy infantry/MC) and what you want the squad to do (sit on an objective, attack enemy objectives) should influence your Tactical Squads' loadouts.
**You should not take a CC weapon, grav or plasma pistol on the Sergeant. Ever. They lessen the squad's 24" range firepower and they scare nobody. Not Orks, not that nasty squad of Terminators, not the rampaging Khorne Berserkers. They're just too expensive and they take away points from your list. If you are nuts enough to take a plasma or grav pistol though, your opponent might give you respect knuckles when your Sergeant immobilizes or one-shots a rampaging Dreadnought.
**Also, this is the edition of MC's and hard-to-kill infantry, not vehicles. Meltaguns can make them too specific in a role is better given to a unit that can do AT and something else at the same time just as well (e.g. a Tri-Las Predator).
**Do not take Heavy weapons in a Tactical squad if you are planning on having that squad be mobile (such as in Mech lists or Drop pod lists). Only put them in units that you plan on having sit in one place for the entire game (combat squad on an objective). Grav-cannons, being Salvo rather than Heavy, are the possible exception to this, but they're expensive - avoid them unless you're also taking a grav-gun and combi-grav to go MC hunting.
**Carcharodon Tactical Marines can take CCWs for 1 point/model (or free if you trade in their bolters) and gain RAGE after destroying an infantry unit in close combat, probably the one situation where they become usable in CC.
**Probably the best Chapter Tactics for these guys are Imperial Fists. Re-rolling 1s for bolt pistols, bolters, heavy bolters, combi-weapons firing as bolters, and storm bolters is sweet. BS4 rerolling 1s is almost the same accuracy as BS5 (normal BS4 is 24/36 chance to hit, but with Imperial Fist Chapter Tactics BS4 is 28/36 chance to hit, which is almost normal BS5's 30/36 chance), and without needing to spend a Doctrine.
**Tacticals can be useful to finish off stragglers from enemy units that has been shot up by your heavy hitters, without sacrificing more important shooting power to finish off a couple of Fearless/Stubborn/ATSKNF models.

*'''Imperial Space Marine (30th Anniversary Release):''' This is a unique, limited-edition model you can add in place of any Space Marine at no extra cost (''and that's all we're going to say about that''). Though stat-wise, he's not any better than a basic marine, he does come with two dangerous weapons: a Disintegrator Combi-Gun (18" S5 AP2 Assault 2, Gets Hot, Instant Death) with INFINITE shots, a Disintegration Pistol (9" pistol version) and a CCW. He's the bane of MCs everywhere, provided he can get close enough to hit them. Keep in mind what the rest of the squad's there for; he's best suited in a Tactical or Devastator Squad, where he won't get screwed over so much for only having a bolter for long-range damage. The only other squad he can go into is an Assault Squad (the others don't have any Space Marines to replace, only Veterans, Centurions, Scouts, etc). He doesn't really fit in well, but RAW you can stick a jump pack on him in an Assault Squad if you really want to.
**The best Chapter Tactic to use with him are the Raptors. Replace a Tactical Marine except for the Sergent. Choose Grav-weapons for the special/heavy weapons and Combi-Bolter for reliable Salvo hits. Give them a Rhino or infiltrate his squad close to the objective and [[Troll|dare your opponent to try and take it from you]]. Two/Three Grav-weapons, the Disintegrator Combi-Gun and Heavy 1 for the rest of the squad makes charging them a bad idea. 

*'''Crusader Squad (Black Templars)''' - Black Templars only, essentially a beefed up Tactical Squad that is capable of taking neophytes as meatshields and a Sword Brother as a Veteran Sergeant for your initiates to survive longer and therefore be able to make the charge once they have gotten within range. The issue here is that you can't take more Neophytes than Templars, so their usefulness as meatshields takes a hit, especially in smaller squads.
**There are two ways to kit out your neophytes for close combat. Pistol/CCW allows a S4 AP5 pistol shot before combat, and 2 S4 attacks at I4 (3 on the charge, 4 if you get Rage). The Shotgun option allows for two S4 shots before combat and a single S4 attack at I4 (2 on the charge, 3 with Rage). The AP5 of the bolt pistol will rarely be more useful than the shotgun's extra shot before Overwatch is even fired, and if Overwatch fells any of your boys, the shotgun loadout's lack of +1A from having two CCW is further diluted by Rage from BT Chapter Tactics. Also keep in mind the shotguns' extra shooting attacks will always hit on a 3+ and "ignore" enemy Initiative, whereas the close combat attacks might only hit on a 4+ or even 5+ (depending on enemy WS) and I5 or higher enemies may slay some of your guys before they can swing.  However, another consideration is that you might accidentally gimp your charge distance if you kill too many models in the shooting phase - shotguns can do this if you run into Termagaunts or the like.
**Black Templars should be Running in the shooting phase to make use of their Crusaders special rule, unless you're close enough to charge (like if your squad used an LRC to get up close). Crusader Squads want lots of Bolt Pistols and CCWs if you are using anything other than 5 man las-plas squads because Crusader Squads should be focused on assaulting. Use tactical squads if you want to sit back and shoot.
***If you wish to switch between these options, assemble your scouts with close combat weapons and pistols, then trim the hands off the shotgun models and glue them to the scouts back as though holstered.
**You can buy power weapons for people other than the Sword Brother, which means that you can actually avoid having a Power Fist or Axe get challenged and murdered. Still not a terribly efficient use of points--Vanguard Vets are probably more worth the investment. Stick to Pistols and CCWs for assault-focused Crusader Squads, the weight of attacks is better for what you're engaging (read: hordes, light vehicles, tarpitting big guys). HQs and other characters can bring the AP 2.
**One overlooked competitive option for Crusaders is grav spam. While a normal tactical squad might take a combi-grav and a grav-cannon for their 5-man squad, you can get a multi-use grav gun and cannon. You could even get a combi, special, and heavy grav all in one 5 man squad with a minimal 10-point Sword Brother upgrade tax (vs. tactical squads needing a full extra 5 bolter goons to sit around and do nothing all day). Not a horrible option if you want a useful troops tax for a Black Templars CAD so you can have their special characters.
** Take note of the wording of the "Righteous Zeal" special rule Black Templars' Chapter Tactics, because your own Gets Hot wounds will also trigger it. So if your enemy is so antsy that they actually avoid firing Overwatch to deny your [[Rage]], this is pretty much the only way to get it. Like everyone else, your plasma pistol might hit and kill something, or your squad leader might die to Gets Hot (1/18 chance). But unlike everyone else, for a large Crusader Squad, you win ''either way''. (note that you still shouldn't buy pistol upgrades, ever.)
** These bad boys get to take a Land Raider Crusader as a dedicated transport. This is rather glorious, since it gives the Land Raider Objective Secured, means that your super assaulty squads can start the game in an Assault Transport, and means you can use the Land Raider for close quarters objective camping. Nice. Do keep in mind that in the age of grav and low-AP guns everywhere, your Land Raider could get immobilized turn one or two before it does anything. A big waste of 240 points. Weigh your options (and your local meta) carefully.  

*[[Scout|'''Scout Squad''']] - Scouts now have the exact same statline as standard Marines, except for a 4+ armor save rather than 3+, gaining Scout, Infiltrate and Move Through Cover in return. This makes Scouts generally a better choice of troops than Tactical Marines. If you run Scouts, you're likely best off running them naked. 11 points for a model in carapace with a BS4 bolter is actually fairly good as far as medium infantry goes, but upgrading them to snipers tends to be a waste of points. The five man scout sniper squad may look good on paper, but 5 BS4 shots is going to lead to about three hits, which will leave you with about a wound and a half before armor. Since Snipers don't have Pinning, this can be summed up as "useless". Don't bother trying to put the hurt on monstrous creatures with this either, since while you might wound on 4s, MCs generally have enough wounds not to care.
**Thanks to Scouting and Infiltrating, Scouts can put a Teleport Homer on the board rather fast and uncomfortably close to your enemy's forces, so keep that in mind if you run Terminators of either flavor.
**One role Scouts are alright at is manning the quad gun on an Aegis. Be sure to give them Camo Cloaks for a 3+ cover, but don't bother with Sniper Rifles. They'll mostly be shooting the quad gun at the nearest flyer, so those rifles will be points wasted.
**One of the classic Scout combos is to take a Techmarine (a Thunderfire Cannon's gunner also counts). Give your scouts Camo Cloaks, put them into a ruin that you "fortify" with the aforementioned Techmarine's special power, and [[Troll|enjoy]] a 2+ cover save.
**According to the wording in the rule book, models choose their weapons individually. Meaning you can take a squad of 5 w/ Bolters and 5 w/ Shotguns and a Land Speeder Storm, and at the beginning of the game, Combat Squad them and stick the melee squad in the Storm while the Bolters hang out in ruins with a Techmarine. The back-line camping Combat Squad is also the only place where Sniper Rifles may be okay.
**One final role a squad might be good at is turn-one tank removal. You take a Land Speeder Storm with a multi-melta and infiltrate it as close to the enemy's biggest, most valuable tank as possible. The speeder Scouts 12" closer to its target, then moves 6" and the squad disembarks 6" (hopefully into some cover). All this should put both the Scout Sarge's combi-melta and the Speeder's multi-melta in melta range, so hope for the best on your to-hit rolls. At only 5 points, you may also want to give the sergeant meltabombs, in case both he and the tank survive turn 1.
** A Veteran Scout Sergeant with a power weapon is a decent buy for melee Scouts in a LSS. Four power weapon attacks on the charge against backline shooty units is nice, or can draw fire away from other units trudging up the board. A Power Maul is a good choice, allowing you to wound most things on 2s and having a decent chance to score a penetrating hit on a vehicle without blowing it up (sparing your squishy marines a lot of S4 hits form the explosion and giving them some cover from the return fire).
**Scouts with Raptor tactics for all intents and purposes have Sniper Rifles sans Precision Shots and with -12" to range for free.
**If you are taking a formation and need a cheap Auxiliary choice, look no further than a 10th company Strike force. Take Sniper Rifles, Camo-Cloaks, and a Heavy Bolter (not necessarily required) on 3, 5 man scout squads. Infiltrate them where you want them and NEVER MOVE THEM. You now have a 36" harassment bubble against enemy infantry, which every once in a while will allow you to allocate a wound yourself or wound with AP2 (Or if you are lucky, both at the same time, perfect for getting rid of Special weapons or sergeants), that has a ''2+ cover save''. They will annoy your enemy AND tank most fire flung at them that isn't a template or Ignores Cover. Just be careful with such small squads because if you roll too many 1s at a time they may be forced to move, and loose their 2+ goodness. 
*** This problem is essentially solved if they are taken as an auxiliary for a Salamanders Flameblade, as they automatically gain Fearless if they don.t move in the movement phase. ''Now the enemy has to kill every model to get them off their perch''