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

====The basics====
*Choose a weapon to shoot with and throw a dice. To hit, you need to score higher than your BS (which may vary due to external modifiers like cover).
* Rolling to wound:

**Attacker's Strength two (or more) greater than target's toughness: 2+
**Attacker's Strength one greater than target's toughness: 3+
**Attacker's Strength equal to target's toughness : 4+
**Attacker's Strength one less than target's toughness: 5+
**Attacker's Strength two (or more) lower than target's toughness: 6+

If the target's toughness is double (or greater) the attacker's strength, then the target is completely immune, the attacker can't damage him. Conversely, if the attacker's strength is double (or greater) the target's toughness, the wounds gain the rule "Instant Death" (meaning any unsaved wounds insta-kill the target).
* There are two ways to kill a tough unit: Either you use a high penetration high damage weapon to greatly reduce the chance of the unit succeeding its armour save , or you can attempt to overwhelm the unit's defense and fire enough dakka into it to make it fail a save. Bring the appropriate amount of dakka to combat a heavy unit, lest you be the one shot to hell.
**Example: Space Marine Terminators '''hate''' Guardsmen, Necron, and Tau bricks because they put out a fuckton of weak shots that will make them inevitably fail armor saves. Or rather than rely on 50 lasgun shots the guardsmen can instead bring a plasma gun that can flush their armor saves and instantly kill them. The plasma gun only needs to cook one terminator to make its points back. Conversely, the terminators can bring a heavy flamer and viet-nam 80% of the guard squad.
*Consequently, using too many units on a weak enemy is a waste of firepower and resources. Every unit who is somewhere can't be somewhere else.
*Although over-kill might be considered bad by some, lady luck might not always be on your side. You want to succeed even if plans A, B and C fail.
*During your shooting phase, assess what target options each one of your shooty units has, and always have your units who only have a single option fire first. The reason for this is if you've got unit A in a position to shoot anything he likes and unit B which only has one thing to shoot at, you want B to take the shot first. If you shoot B's target with A first instead, you run the risk of destroying it or breaking their morale, and you'll feel like a complete moron for depriving B of anything to shoot at.
*Another thing that is good to remember is which guns to fire first. Always fire blast weapons first, because the number of wounds they deal is always equal to the number of units in the squad at best, whereas regular guns can deal as many wounds as they hit.