Field Manual

Last Light at the Aqueduct

Tactical decision game #1 — five minutes, one FRAGO, no radio

August 1, 2026 · Phaseline Team

A tactical decision game — a TDG, or tactical decision exercise — is one situation, one hard problem and a short clock. You read the situation once, you decide, and you deliver the decision out loud as an order. There is no solution printed at the bottom of the page, because the point is not to be right. The point is to be fast, clear and able to say why.

This is the first of a series. Each scenario ships with the overlay as a picture and as an editable TacMap scene, so you can run it on a screen, project it, or print it for the table.

The situation

You are the squad leader of Alpha Squad, 2nd Platoon, 3rd Battalion. The unit is deployed in an arid river valley on counter-insurgency operations. The local militia is armed with automatic rifles, light machine guns, and occasional mortars and RPGs.

Today your platoon — reinforced by an attached medium machine gun team — is conducting a route clearance and security patrol to locate and destroy hostile forces in the area. Twilight is roughly thirty minutes away.

Your squad is the point element. You are advancing north inside a knee-deep, muddy irrigation canal, about 200 metres ahead of the platoon's main body.

As your lead fireteam steps across an intersecting dirt track at the northern edge of the canal, a concealed tripwire IED detonates. Your lead rifleman takes a severe traumatic leg injury.

Immediately after the detonation, enemy forces inside the western farm compound open heavy, sustained automatic fire. The platoon leader is hit and down.

The volume of fire from the compound has Bravo and Charlie Squads pinned flat in the open. The platoon medic low-crawls forward to your canal position under fire, followed shortly by the attached machine gun team. The medic reports that the lieutenant is critically wounded and unconscious. The platoon radio operator is pinned in the open near the lieutenant, which leaves you without communications.

The fire coming into your canal position is sporadic. Bravo and Charlie are locked in and cannot manoeuvre, although they are returning fire. You have no contact with your platoon sergeant.

The sun drops below the horizon in less than thirty minutes.

What do you do?

Overlay of the ambush: the platoon strung out north–south in the irrigation canal east of an abandoned farm compound, the point squad at the IED strike on the northern track, the platoon leader down 200 metres behind, and the aqueduct running along the eastern flank.
The situation as your team leaders would see it on an overlay. Scale 1:3,000, contour interval 5 m. The enemy diamond carries a question mark because that is genuinely all you know. Open this scene in Phaseline

The requirement

Within five minutes:

Reading the overlay

The picture is drawn to the same standard the platoon would use for a hasty overlay, and it is worth reading properly before you start the clock.

What makes this one hard

Name the tensions before you start writing, because the order you resolve them in is your decision:

You will not solve all five. Decide which two matter in the next ten minutes, and be able to say why the other three can wait.

Run it, then run it again in a month with the same group. The second set of answers is the one that tells you whether anything stuck.

Scenes in this post

Each diagram above is a real, editable TacMap scene. Open it in the editor or download the file.

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