The Tactical squad is the most basic and ubiquitous Space Marine unit. As a Troops choice, they have several advantages over most. They’ve got an above average statline, a great armor save, and an excellent basic gun, and they have the option to take a special weapon and a heavy weapon, as well as weapon upgrades for the Sergeant. This allows the Tactical squad to fulfill a variety of roles on the battlefield. Combine this with And They Shall Know No Fear and you get a durable, reliable objective holder that can help take out the enemy. The downside here is that you have to pay for all of this, so a fully equipped Tactical squad will cost as much as the Elite squads from many other codices.
The biggest change in this codex is that 5 Marine squads can take heavy weapons again. This allows the most basic squad configuration, 5 Marines with a long-range heavy weapon. These guys will hold backfield objectives while peppering the enemy with fire and are quite easy to use.
Alternatively, you can take a more aggressive squad. These squads need to be larger, preferably 10 strong, because you will need the extra bodies along with the extra bolter shots. You should definitely take a special weapon to augment your firepower: a flamer for torching light infantry and to defend against assaults, a meltagun for killing vehicles, or a plasma gun for targeting heavier infantry and light vehicles. It’s worth noting here that the plasma gun isn’t an assault weapon, but that’s not really a downside here. You will rarely want to assault with your Tactical Marines; they just aren’t very good at it against most targets. For this style squad, you will rarely want to take a heavy weapon. It’s more points for a weapon you will usually only be snap firing. The Sergeant should take a combi-weapon that matches the special weapon, giving you more reliability against your chosen target. Once again, Tactical Marines are not great in assault, so I’m not a big fan of taking a power weapon or fist on the Sergeant. If you assault, it will be against an enemy that you won’t need a power weapon to beat (like Fire Warriors). If the enemy assaults you, it will likely be with a unit that you won’t hurt much with 2 power fist attacks. It will only really help in assaults against similar units, and in those cases both players will prefer to keep shooting. If you charge, it will only be to tie up the other unit for the rest of the game.
Finally, you can take a full squad and give them both a special and heavy weapon. This is to allow you to make best use of Combat Squads, which allow you to split into two 5 Marine squads at the beginning of the game. In general, you’ll put a squad with a heavy weapon on your backfield objective and then have the other squad, with the Sergeant and special weapon, advance to take forward objectives. If it turns out that you need larger units, for example because the mission awards victory points for each unit destroyed or because you need very durable scoring units, then you leave the squad intact and run it like the previous pattern with a bonus heavy weapon. It's important to note that, in an exception to normal rules, both combat squads can ride in the same transport. This is pretty huge as it gives you a lot of flexibility when you disembark. For example, a combat squad with a flamer can disembark forward to flame the enemy while a combat squad with a heavy weapon can disembark to the rear to keep itself safe and provide covering fire.
I’ve been going back and forth on taking a Veteran Sergeant. The extra attack is pretty meaningless for a Tactical squad, but that LD 9 is important. Marines don’t benefit as much as they used to from falling back due to the changes to And They Shall Know No Fear (they don’t get a 3” consolidation move on top of their 6” move any more), so it’s better to hold position. In addition, units in a shaken or stunned vehicle can shoot normally if they pass a LD test, making LD 9 a massive improvement in reliability for any unit in a transport. Once again, if you want to take advantage of Combat Squads, that changes the situation a bit. Your Veteran Sergeant will only pass his leadership to one of the squads, even if they're both in the same transport, so I generally avoid the Veteran Sergeant upgrade if I'm planning to split the squad.
The final thing to consider with your Tactical squad is whether or not to take a transport. The small, heavy weapon based squads really don’t need one as they’ll be pretty stationary, but they could take a Razorback for some extra firepower. The larger squads really should have a Rhino or Drop Pod, depending on how you want to deploy your army. Either performs the duty of getting your squad into range to make those bolters really count. The Rhino has the advantage that it can be used to redeploy the squad later in battle, while the Drop Pod is way more difficult to destroy before it initially deploys the squad. A final note worth mentioning is that any transport dedicated to a Tactical squad in a Battle-Forged army will receive Objective Secured. In my mind, that makes the transport an obvious addition as it adds another of these very valuable scoring units to your army at a bargain price.
The Tactical squad may be the only unit in the army that really benefits from every Chapter Tactic. Ultramarines Tacticals can be twin-linked for a turn, while White Scars will be exceedingly hard to pin down with Hit and Run. This makes them work similarly to the Combat Tactics from the last codex. Imperial Fists have more accurate bolters and even make good use of the much maligned heavy bolter, so are best used for clearing infantry. Black Templars don’t get much from Tactical squads, but that’s why they have Crusader squads. Iron Hands Tacticals are more durable, and you’ll really see the benefit of their Feel No Pain if you take a lot of Tacticals. Salamander Tactical Marines make excellent use of flamers (and meltas if you take Vulkan He’stan). Raven Guard Tacticals can use Scout to get into bolter range a turn faster and really put pressure on the enemy.
How do I play them?
As I’m sure most of you know, I play with Imperial Fist Chapter Tactics. This leads me to specialize my Tactical squads for killing other infantry while my Tank Hunting Devastators deal with enemy vehicles. I usually take a flamer and heavy bolter in 10 Marine squads, and leave the Sergeant with just a bolter. The whole squad rides in a Rhino. In the past, I kept my Tactical squads together, wanting to concentrate my firepower. Recently, I've been splitting them but advancing them together in their Rhino. This works much better than keeping the squad together or leaving 5 marines in the backfield. It provides amazing flexibility in mobility and firepower, and does a great deal to mitigate the worst problem for Tactical squads, enemy assault. Suddenly, that nasty assault unit can only annihilate 5 marines when it assaults rather than 10, and is much more likely to finish their target off in one round of combat, leaving them open to your firepower. That makes a massive difference.
I normally run two or three such squads, concentrating them on one area of the field to saturate the enemy with bolter fire. Once they’ve done their damage, they can disperse to hold objectives and try to survive to the end of the battle.