(Revisit) Battle Drill 1A (Cross Post from Patreon)
Note: This is from my personal Patreon, if you would like to see the original (identical) writeup, follow this link

To kick off the presence on this website, I figured I'd do my simplification/explanation of some of the major Battle Drills the US Army employs. Reference is the Ranger Handbook, FM3-21.8 (Infantry Platoon and Squad), and myself having been taught this and rehearsed this while in the service.
Note: To replicate this would presuppose many things, the main thing being the unfettered access to belt fed machine guns, grenade launchers, grenades, and automatic rifles. In conjunction with that, this presupposes you have access to minimum a squad that has been pre-trained and rehearsed all of this. Regardless of having the aforementioned, I still think you should give this a look, be it for your own professional development (mil/LEO), concerns about the future (citizen self defense force, partisan, freedom fighter, etc.) or for recreational use (airsoft, paintball, VR).
Lets start off with Battle Drill 1A, the Squad Attack. The reason why I start with this and not BD1, is that BD1 is a platoon task. BD1A is a squad task. For these purposes a squad will be defined as eight to ten personnel (most commonly nine), a platoon will be defined as three or more squads (usually four squads) of eight to ten men each. The squad has a sub-unit, the team/ fireteam, that is three to four men.
BD1A is an immediate action drill to be done when contact is made by the squad with an enemy force. The most basic building block of all the Battle Drills, this one, should be perfected to an art. The squad in question is on patrol and encounters an enemy patrol. The enemy has not noticed your squad and the decision is made to attack, based off of the size and disposition of the enemy force. You, as the squad leader, tell one of your teams (on patrol your lead team) to get on line. They will get in line with each other, facing the enemy force, while taking up covered and/or concealed positions. Once you, the Sqd Ldr, are satisfied, you will let the team set up in cover (from this point on referred to as the Support By Fire or Support team) what direction you will take the second team to engage the flank. When you step off with this second team (known as the Assault team), your support team initiates fire on the enemy, taking care to not shoot in the direction you and your assault team are flanking from. This will look something like the image below.

Key: Blue= Friendly, Red= enemy, Purple= Sqd Ldr, Yellow= Weapons fire, Black= movement
Once you and your assault element arrive at a spot where you think you can present a strong base of fire and has a good covered/ concealed route to assault from, you will get your assault team on line, and you will give the signal to the support team to shift fire. They will shift their suppressive fire to the direction opposite of where your assault will come from. The signal can be given by radio, smoke grenade, whistle, flare, mirror, etc. Once the signal is given to shift fire, you and your assault team will engage the enemy force, using cover, concealment, explosives, machine guns, etc. to overpower the enemy as you advance. By this point, most and perhaps all of the enemy force should be neutralized, be it dead, wounded, or surrendered.

As the Squad Leader and the assault team push through, the support team leader (or Squad Leader with a designated signal) will order his men to lift fire. This means they will fire to the furthest point away from the assault team, ceasing fire once the assault team crosses in front of them. The assault team, as they make their push, will follow whatever predesignated procedures they have for actions upon encountering dead, wounded, or surrendering enemy (disabling weapons, "dead checks", subduing prisoners). They will clear the area deliberately while on line, in order to present a strong skirmish line should more enemy pop up and continue to fight.

The assault team cross though, stopping and pulling security once the Sqd Ldr determines a good location off of the enemy zone that is defensible. This will create the LOA, or Limit of Advance, a term basically saying "this is the furthest the teams will assault before stopping and pulling security". Once the assault team is emplaced at their LOA, they will pull security outwards in case there is a nearby enemy force that will react to the firefight. At this point, the Sqd Ldr will give the signal for the support team to pick up and assault through the enemy zone. They will follow the same procedures as the assault team, only they are moving in a somewhat perpendicular direction to the initial assault.

Once the support team has made their push, they will stop at the LOA for their team, gauged off of the last man from the assault team. He will call out "LOA!" or otherwise mark himself or his area as the point to where the support team will finish their assault and set up security on their own LOA. From here, the Sqd Ldr will link up with the assault and support team leaders, and will have them perform two tasks: get the LACE report (Liquids, Ammo still on hand, Casualties or injury incurred, and Equipment considered mission essential or sensitive like NODs or radio) from the team members, and prepare for follow on actions. Follow on actions usually include stepping off on a new patrol away from the engagement area (thereby making this a Raid) however they can be changed to occupying the location to await reinforcements or to stage an ambush on any enemy quick reaction forces. Accountability of all squad members is assured, and once the LACE checks and follow on planning is done, the Sqd Ldr can either send out his designated teams for post engagement actions, or make a plan to step off of the area and continue mission. Post engagement actions can include Enemy Prisoner of War/Search teams (to gather any intelligence worthy items or materials from the enemy, to include prisoners), Aid and Litter team(to render aid to any wounded or killed, and, depending on the nature of the engagement, recover sensitive items from killed friendly squad members), and Demolition team (to destroy any valuable equipment left by the enemy or destroy a fighting position to prevent future use).

That is my rundown of BD1A, some people might argue I went too far or didn't do X vs Y, but this is the basics of the drill. I tried to make it as easy for a layperson to read and understand (pardon the drawing quality) and tried not to keep it too mil specific. Below I will write a simplified listed version, my goal is for you to screenshot and disseminate this to interested parties, my goal is to help the good and virtuous with this. As always, leave any feedback in the comments or PM me, I will try as best as I can to respond. Thank you! Battle Drill 1A: Squad Attack
Squad on patrol encounters enemy force, Squad Leader decides to fight.
Squad Leader designates support team, they will provide suppression onto enemy force.
Squad Leader designates assault team, tells them direction of flank and signal.
Squad Leader tells support team direction of flank and signal, departs with assault team.
Squad Leader gives signal to support team to engage.
Support team engages enemy force, takes care to not engage direction of flanking assault team.
Squad Leader gives signal to shift fire, gets assault element ready to assault through enemy zone.
Support team shifts fire away from assault team, takes shots at targets of opportunity.
Assault team and Squad Leader push through on line, deliberately clearing enemy zone.
Squad Leader designates Limit of Advance, Assault team sets down, pulls security.
Squad Leader gives signal, support team picks up and assaults through enemy zone.
Support team reaches Limit of Advance, pulls security.
Squad Leader coordinates post engagement actions, Team Leads get LACE reports from teams, crossload as necessary.
Squad Leader briefs new objective, Squad steps off or performs objective.