How to Draw Line on Arma 3

Marking the Map

The map is extremely useful for planning and coordination purposes. One of our main methods of conveying information to other players is via using "map markers" to indicate points of interest, waypoints, objectives, landing zones, enemy positions, and more.

Below are some guidelines for making the most of the map. Heed these and things will go more smoothly for everyone.

How to Mark the Map

To place a mark on the map, double-click. You can enter text by typing, and then Enter will finalize the mark.
To change the icon of a map marker, press up/down arrow until you get to the marker you want to use. This (and coloring the marker) only works until you place it with Enter.
To change the color of a map marker, hold Left Shift and press up/down arrow to cycle through the colors.
To delete a mark, hover over it with the cursor and press Delete.

ACE Map Tools

To use map tools the Map Tools item is required.
Open the map M (Arma 3 default key bind Map).
Press the self interaction key Ctrl + ? Win (ACE3 default key bind Self Interaction Key).
Select Map tools.
Select the type of tools you want to use.
Note that you can drag the Roamer (map tool) around with LMB and rotate it with Ctrl + LMB.

To draw lines the Map Tools item is required.
Press ALT + LMB to start the line, left click again to end it.
To delete a line press Del around the center of the line.
Note that you can change the color of the lines by clicking on one of the coloured column on top of the screen (While the map is opened).

Tips

Map markers are visible to the chat channel you are "tuned" to when placing them. Ensure that you place markers in Side, Group, or Vehicle chat. Placing them in Global chat will allow the enemy to see them, which is generally considered to be bad for your long-term survival.
All map marker text should be written as succinctly as possible using abbreviations and acronyms. For instance, "aa" is anti-aircraft, "inf" or "ei" is enemy infantry. Alpha Squad becomes "A", waypoint becomes "wp", and so on.
Try to use the logical symbols when adding map markers, as time and the situation permit. See the picture below for sample markers.
Adding a time to the mark can be useful in some situations. When doing so, use the in-game time (which can be seen in the upper-right of the map) so that players in different real-world time zones are not confused by it.

A typical map plan for a platoon helicopter insertion

Reading the Map

Right & Up

Reading a map is easy once you know the basics of it. The main thing to remember is that the grids must be read right, and then up. See the following screen for an illustration of how it works. Due to the fact that the map grid is composed entirely of numbers, it's important that you do not transpose them, else you're likely to send someone far, far away from where you needed them to go.

Reading a six-digit map

Note that depending on the map zoom, you may see two, three, or even four numbers per horizontal or vertical grid. This reflects the precision of the coordinate. For example, a six-digit grid (3+3) defines a square that is 100 meters on a side. A four-digit grid (2+2) defines a square that is one kilometer on a side. An eight-digit grid is 10 meters on a side, while a ten digit grid is 1 meter on a side.

Depending on the difficulty settings and mods used, you may have a mouse-over tooltip that displays the elevation and six-digit grid of wherever your cursor is. While this is a handy tool, knowing how to read grids correctly is an essential skill to have.

Reading a eight-digit map

Since the arma map does not have more than 3 figures the most accurate grid one can give is 100m2, but by imagining a the lines inside the 6 figure grid, we can produce a 8 figure (or even 10) figure grid reference by guessing the approximate line inside both axis. Eight figure grid references are essential for communicating fire support where accuracy within 10 meters or less is essential.

The Grid Scale & Contour Interval

Arma 3 features a grid scale that dynamically scales based upon how zoomed in or zoomed out you are. This scale shows both a linear distance guide and a contour interval guide. The contour interval means that each contour line represents x-meters of vertical space. Thus, if there are three contour lines of difference between your position and another position, you multiply that number times the contour scale to come up with the amount of vertical difference between the positions.

Points of Elevation & Hill Numbers

Note also that the numbers scattered around the map indicate points of elevation. These occur either at the top of a protrusion (such as a hill) or the bottom of a depression (such as a valley). When communicating map locations over voice chat, numbered hills can be referred to as "Hill 123". Pay attention to whether a specific hill can be seen from zoomed-out view or if someone must zoom-in to the map for it to appear, as this can be confusing to players if not specified. If the terrain you're in is very hilly, ensure you're specific about which one you mean - oftentimes there will be multiple points of elevation with the same altitude.

You must be able to use a compass, and communicate bearings correctly.

The Compass

How to Read the Compass

The compass is graduated three ways: The first and simplest is via the cardinal North, South, East, and West directions. After that it is graduated in degrees - 0 to 359. This is the inner, larger set of numbers, and should be used when calling out specific target bearings. The final outer set of measurements are known as "Mils", and generally do not have a use aside from communicating with artillery units. In the event that you do ever use mils as a direction call, remember that the numbers need two zeros after them. The "2" marker on the outer ring is actually 200 mils, for example.

Note also that the Arma compass has illumination on it for better readability at night. Also note that the compass, like other gear items, may or may not be available based on the player loadout in a mission. Also, in Arma 3, the compass can take a moment or two to fully stabilize once it has been turned.

Communicating directions

When calling out compass bearings, the correct way is to say e.g. "BEARING 320" or "BEARING 020" (ZERO-TWO-ZERO)

Remember: When calling out bearings on a radio to think about the postion of the units on that frequency. Bearings are best used via direct chat, as anyone who hears you will be able to quickly locate the target.

The compass, as seen in daylight and at night

REFERENCES
UNITAF Standard Operating procedures (SOP) are adapted primarly from US Army Training and Doctrine Command (TRADOC). Our written and audio procedures are a combination of the following primary source materials, as well as our own learnings, modifications and adaptations:
- US Army Techniques Publication, Infantry Platoon and Squad (ATP 3-21.8)
- Soldier's Manual of Common Tasks Warrior Leader Skills Level 2, 3, and 4 (STP 21-24-SMCT)
- The Warrior Ethos and Soldier Combat Skills (FM 3-21.75 / FM 21-75)
- Leadership Development (FM 6-22)
- Dyslexi's Tactics, Techniques, & Procedures for Arma 3 (TTP3)

How to Draw Line on Arma 3

Source: https://unitedtaskforce.net/training/sop/basic-infantry/using-a-map-and-compass