NEWS FROM THE FRONT 

19 JAN 17 

 CPT Nick Morton 

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The Mounted Combined Arms Rehearsal

CPT Nick Morton

5th Battalion, 20th Infantry Regiment

During our recent rotation to the National Training Center (NTC), 5th Battalion, 20th

Infantry Regiment, “Sykes’ Regulars”, refined our use of the mounted combined arms rehearsal 

(CAR). The mounted CAR, when designed and executed properly, adds value to the traditional 

terrain-model CAR, and provides the additional benefit of exercising our mission command 

systems.

Rehearsals are arguably the most important step of the planning process. General George 

S. Patton is credited with the statement, “A good plan, violently executed now, is better than a 

perfect plan next week.” Over my career I have heard a poignant variation on this famous quote: 

“A great plan with a bad rehearsal will result in a bad mission. A weak plan, well-rehearsed, will 

result in a successful mission.” Rehearsals identify friction points and allow the commander to 

ensure everyone understands his intent prior to the operation. 

“Rehearsals are the commander’s tool to ensure staffs and subordinates 

understand the commander’s intent and the concept of operations. They allow 

commanders and staffs to identify shortcomings in the plan not previously 

recognized. Rehearsals also contribute to external and internal coordination, as 

the staff identifies additional coordinating requirements.” – FM 6-0, Commander 

and Staff Organization and Operations 

While the combined arms rehearsal is the preferred type of rehearsal, there are many 

methods of rehearsal that a commander can choose to execute the CAR. The figure below, from 

FM 6-0, Commander and Staff Organization and Operations, should be familiar to many. This 

figure depicts the inherent trade-offs between different methods of rehearsal, when compared 

against the following criteria:

• Time Used

• Resources Required

• OPSEC Risk

• Leader Participation

• Understanding Gained

Most units attempt to 

conduct their rehearsals in the 

upper-right area of this chart, if 

time and resources permit. Our 

battalion is no different. A full 

dress rehearsal, while providing 

the maximum amount of 

understanding, also requires 

extensive resources to execute. A 

blank fire run prior to a platoon 

live fire exercise is a prime 

Figure 1. The Mounted CAR Combines elements of the Network, Digital Terrain 

Model, Key Leader, and Full Dress methods of rehearsal.

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example of a full dress rehearsal. The terrain-model rehearsal is the most popular rehearsal 

method (FM 6-0). When most leaders envision a brigade or battalion-level CAR, it usually 

includes a large terrain-model with operational graphics and unit icons. Construction of the 

terrain-model is often time-consuming and resource intensive. 

The Regulars’ Mounted CAR is effectively a key leader rehearsal, with elements of the 

full dress rehearsal and the network rehearsal methods included. Our transition point between 

current operations (CUOPS) and plans happens immediately following the OPORD briefing. 

This transition point places the rehearsal firmly within CUOPS’ area of responsibility, thereby 

forcing CUOPS to master the plan prior to the rehearsal. 

Rehearsal Preparation 

CUOPS begins constructing JCR “mini-graphics” as soon as possible. The operational 

graphics, information collection, and fire support overlays created by the planners are 

concurrently developed in analog and digital formats. As a mounted formation, our JCR systems 

provide our common operating picture. As a Stryker formation, we often outpace our FM range 

during offensive operations, and the JCR is a critical mission command system for maintaining 

shared understanding and situational awareness. By building JCR “mini-graphics” for the 

mounted CAR, we are able to replicate how we fight and concurrently test our mission command 

systems. 

The mini-graphics are 

created on the map over the 

intended rehearsal site. While an 

area as small as 2Km by 2Km can 

be used, we have used areas as 

large as 4Km by 4Km for our 

mounted CAR. We consider the 

following selection criteria when 

looking for a rehearsal site:

• Proximity to our subordinate

elements TAAs - as centrally

located as possible

• Enemy threat - specifically

the threat of observation and

indirect fire

• Terrain – maneuverable by

Strykers with good

observation across the

rehearsal site

Once the site is selected, the mini-graphics are built on JCR. We begin building our 

rehearsal graphics from the LOA backwards. This technique ensures two things. First, the spatial 

relationships between our graphics at the decisive point will be accurate because we will not run 

in to a piece of restrictive terrain that is outside the rehearsal site. Secondly, by building the 

Figure 2. JCR "Mini-Graphics" are relatively quick to construct, since they do not 

have to be tied to terrain or specific grids. An approximate replication of the 

spatial relationships between the real Operational Graphics is the only 

requirement.

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graphics backwards, we prioritize immediate placement of the most critical graphics, allowing us 

to execute the rehearsal quickly if our mission timeline changes. 

In practice, creating the mini-graphics is not overly time-consuming. It will take one 

sharp Lieutenant or NCO about an hour to replicate all operational graphics and fire support 

graphics for the mounted CAR. The mini-graphics, however, are not the only required part of the 

model. While the JCR mini-graphics provide a common operating picture for the rehearsal, that 

shared understanding is immediately lost when our leaders dismount toward their objectives. To 

remedy this problem, we establish an additional terrain model on the ground, depicting key 

graphics that will affect our dismounted fight. By doing this, we ensure there is something on the 

ground at the rehearsal site that mirrors the graphics in the JCR. We try to keep these models 

simple. A few pickets and some engineer tape represent our phase lines, while some strategically 

placed MRE boxes represent urban objectives. 

Rehearsal Execution

The Regulars’ Mounted CAR is controlled from the Battalion 

Command Post (CP) by the Battle Captain, just like the subsequent 

operation. The Main CP is fully manned by all Warfighting Functions, 

and the Tactical Command Post (TAC), if used, is also manned. Figure 

3 shows a rough template of CAR attendees and their respective 

locations. In practice, required participants for the CAR are 

determined by the Battalion Commander based on the following 

criteria:

• Ongoing operations

• Enemy threat

• Ongoing preparations

• Task Organization

• Time available

• Complexity of the operation

Our general rule of thumb is that any leader maneuvering a 

separate element on the battlefield must attend the CAR. The PL of an 

attached Sapper Platoon, therefore, would attend the CAR. 

The CAR begins with maneuver elements arrayed on the JCR 

Mini-Graphics at one of three locations, based on the commander’s 

guidance and time available: 

• The Tactical Assembly Area (TAA)

• At their templated positions during the start of a new phase

• One phase line back from the probable line of deployment

Once arrayed, the rehearsal begins with a radio check in 

sequence for all participants, further validating our mission command 

systems prior to execution. Typical terrain model CARs often involve an 

Regulars Mounted CAR

Key Participants by 

Location

Battalion Leadership

BN CDR – RHXL Site

BN CSM – METT-TC 

BN S3 – RHXL Site

BN XO – Main CP

Company Leadership

CO CDR – RHXL Site

CO XO – METT-TC

CO 1SG – METT-TC

CO FSO – RHXL Site

PLT LDRs – RHXL Site

Key Staff

S1 – METT-TC 

S2 – Main CP

AS3 CUOPS – Main CP

AS3 PLANS – Main CP

S4 – METT-TC

BN FSO – METT-TC

MEDO – RHXL Site

Specialty Platoons

Scout PL/PSG – RHXL Site

Mortar PL – RHXL Site

MGS PL – RHXL Site

Distro PL – METT-TC 

FAS/MAS – RHXL Site

Attachments & Enablers

Engineers – RHXL Site

Retrans Teams – RHXL Site

Enablers – METT-TC 

Figure 3. CAR Attendees.

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orientation to the terrain model and a recitation of Task 

Organization, the Mission Statement, and the Commander’s 

Intent. This technique can often cause a CAR to look and feel 

more like a briefing than a rehearsal. We attempt to eschew this 

approach as much as possible. Our phase-by-phase agenda, seen 

in Figure 4, has minimal scripted portions. The Battle Captain, or 

AS3-CUOPS, briefly sets the stage for each phase and then turns 

it over to the S2 and Scout Platoon Leader to describe the enemy 

situation. From this point, the CAR runs off the execution 

matrix, just as we would fight the mission. 

Commanders and Platoon Leaders do not simply brief 

over the radio, but call up their reports over the Battalion 

Command Net as they would during the operation. Maneuver 

elements are encouraged to cut into the net and call up their 

reports as they identify their triggers for movement. Likewise, 

the movement of sustainment assets, retransmission teams, and 

fire missions are called in-stride as each phase unfolds. Fire 

missions are called over the fires net and announced over the 

command net so that every element has visibility on the fire 

support plan during the rehearsal. While prompting is sometimes required from the CP, it is more 

common to have to halt a maneuver element briefly during the CAR in order for all other 

elements and enablers to set the conditions prior to the next critical event. Measured intervention 

from the CP is absolutely critical to a successful rehearsal. Typically, Commanders and Platoon 

leaders have a thorough understanding of their unit’s mission, but in a time-constrained 

environment, they may not fully grasp the synchronization of actions at the Battalion level. The 

Battle Captain and Battalion XO must have the freedom of maneuver to pause or prompt certain 

elements in order to keep the rehearsal on track and in sync with the execution matrix. 

The loosely framed CAR agenda lends itself to the addition of injects and contingencies. 

Our commonly used injects often take the form of: 

• Casualties (BN CSM)

• Unexpected enemy action (S2)

• Unexpected friendly action (CUOPS)

• CBRNE attack (CHEMO)

• Branch Plans and Sequels (CUOPS)

A properly planned and executed mounted CAR will take approximately one hour for the 

first iteration, with an additional thirty to forty-five minutes for a re-set or second iteration with 

new contingencies.

Strengths and Weaknesses of the Mounted CAR

As with any chosen method of rehearsal, the Regulars Mounted CAR has advantages and 

disadvantages. 5-20th has been using this method of rehearsal for approximately 18 months, and 

we have developed a thorough understanding of its strengths and weaknesses. Additionally, our 

Mounted CAR Agenda by 

Phase

1. Phase Begins - CUOPS

2. Phase Ends – CUOPS

3. Critical Events – CUOPS

4. Friendly Situation Updates -

CUOPS

5. Intel Update – S2

6. Information Collection – S2/

RECON PL

7. Trigger-Action-Move

8. Fires

9. Trigger-Action-Move (repeat

until Phase is complete)

10. Enablers

11. Sustainment – S4/ Distro /

MEDO

12. Phase Ends – CUOPS

*Repeat for all phases of the

operation*

Figure 4. Phase-by-Phase Agenda

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leaders have become comfortable with the technique, which is critical to the rehearsal execution. 

The strengths and weaknesses of our mounted CAR are listed below in Figure 5. 

The mounted CAR is not a panacea. During our recent NTC Rotation, we only employed 

the mounted CAR twice, often using other methods based on the trade-offs listed above. 

However, given adequate time, we still rely on the mounted CAR as a reliable technique to 

achieve shared understanding above and beyond a typical terrain model rehearsal. 

Strengths

• Situational Understanding: Second only to a FullForce Rehearsal

• Leader Participation: Equal to Full-Force

• Resources: Less than a Terrain-Model CAR

• Synchronization: The absence of the reviled “CAR

Script” forces leaders to fight off the Execution 

Matrix and ensures triggers are learned, not briefed

• Observer Effect: The Mounted CAR does not lend 

itself to easy observation. There are no shaded 

camo-net areas with folding chairs. A senior leader

who wishes to observe will likely go unnoticed by

most participants. By mitigating the Observer Effect,

we ensure that our rehearsal does not devolve into a

briefing.

Weaknesses

• Time: Preparation and Execution time is similar

to a Terrain-Model CAR

• Effort: Similar to a Terrain-Model CAR

• Space: Requires a large amount of open ground

• Security: Similar OPSEC risk to a Full-Force 

Rehearsal

• Learning Curve: New leaders will take a few

repetitions to adjust and embrace the technique

Figure 5. Strengths and Weaknesses of the Mounted CAR

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