Autocad Command Line Basics
The command line is where everything happens in AutoCAD. Type the command, hit Enter, and the program does what you asked. It sounds simple because it is, but the way people approach the command line determines whether they finish a drawing in twenty minutes or two hours. I still keep a printed cheat sheet taped to my monitor even after fifteen years. Not because I forget commands, but because muscle memory is faster than lookup when the deadline is looming. Here is the stuff you will actually use. The rest is noise until you need it. L (Line) - Draws line segments. Click start point, click end point, keep clicking to extend. Press Escape or Enter to stop. Nothing revolutionary. But if you don't have OSNAP enabled, every line you draw will be approximately wrong and you will waste an hour chasing dimension mismatches later in the day.
C (Circle) - Creates circles. Three-point mode, center-radius, diameter. Most people default to center-radius because it is faster. I found that three-point mode saves time when you are connecting arcs to existing geometry and don't know the exact radius. REC (Rectangle) - Draws rectangles. Four points. Set corners. Use DIMINPUT to turn off automatic dimensioning while you draw if you want clean geometry. O (Offset) - Copies geometry at a set distance. Parallel lines, walls, pipe routes. This is one of the most important commands in the entire package. Set your offset distance first, then click the object. I once spent forty-five minutes trying to trace a floor plan by hand when I should have just used OFFSET across a single wall line and dragged it forty times.
M (Move) - Relocates objects. Pick objects, pick base point, pick destination. The base point matters. Pick somewhere useful. I usually pick the corner closest to my target rather than the object center. CO or CP (Copy) - Duplicates objects. Same workflow as MOVE. The difference is copy leaves the original in place. You can also hold the Alt key while using MOVE to make it act like COPY without typing a different command. RO (Rotate) - Rotates objects around a base point. Positive angles go counterclockwise by default. This trips up people constantly. If you need clockwise rotation, use a negative angle or hold Shift while clicking to flip the direction interactively.
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SC (Scale) - Resizes objects proportionally. Type the scale factor. Greater than one enlarges. Less than one shrinks. The common mistake is scaling from the wrong base point and ending up with geometry floating nowhere near where it should be. Always pick a known anchor point. TR (Trim) - Cuts geometry to a boundary edge. There are two modes. The modern version automatically treats all visible objects as cutting edges unless you specify otherwise. The classic version requires you to select the boundary first, then the objects to trim. New installations default to the modern behavior, but some offices still force TRIMMODE equal to zero to keep the old workflow. Check your system variables before you start trimming if the behavior surprises you. EX (Extend) - Lengthens geometry to meet a boundary. Same two-mode behavior as TRIM. Works symmetrically. Learn to use it alongside Trim because most edge correction happens in alternating pairs of those two commands.
F (Fillet) - Connects two lines or arcs with a curved segment. Set the radius first. A radius of zero creates a sharp corner by extending or trimming the lines to meet. This is how I clean up almost every unclosed polyline in a drawing. Use PJ to join the resulting segments into a single object. J (JOIN) - Merges collinear or connected arcs, lines, and polylines into a single object. Essential after using FILLET with radius zero. Without JOIN, you end up with dozens of individual segments that behave differently during hatching, dimensioning, and plotting. PE (PEDIT) - Edits polylines. Can convert lines and arcs into polylines, close open polylines, adjust vertex width, fit curves, and join separate objects. PEDIT is deeper than most people give it credit for. The fit and smooth options create spline approximations that are useful for topology and survey data but will get you in trouble if your output needs to plot at a known tolerance.
H (HATCH) - Fills a closed area with a pattern. Select the boundary, pick a pattern, adjust scale and angle. The boundary detection can fail silently if there are gaps smaller than your precision threshold. Use BOUNDARY command to generate a polyline from a picked point instead of relying on hatch auto-detect when dealing with complex floor plans. I learned this the hard way when a hatch silently filled the wrong region and no amount of retrying fixed it. DIMLINEAR, DIMANGULAR, DIMRADIUS, DIMDIAMETER - The standard annotation commands. Linear for horizontal and vertical distances. Angular for angles between lines. Radius and diameter for circular features. Annotation scaling matters here. If your drawing is in model space at full size and your viewport scale is one inch equals fifty feet, you set the annotation scale in the status bar so dimensions appear correct when plotted. Get this wrong and your title block dimensions will be tiny slivers or enormous obstacles. LA (LAYER) - Opens the layer properties manager. Layers are not optional. Every professional workflow is built on them. Separate your geometry, annotations, dimensions, and hidden lines onto different layers. Turn layers off instead of deleting objects when you need to hide something temporarily. Deleting creates undo bloat and breaks references.
VLA (MATCHPROP) - Also accessible as MA. Copies properties from one object to another. Line weight, color, layer, linetype, transparency. I use this constantly when cleaning up drawings received from other offices. Someone sends a file where everything is on layer zero with random colors and you spend twenty minutes with MA fixing it instead of starting the actual work. UN (UNITS) - Sets the drawing units. Architectural, decimal, fractional, scientific. This setting affects how dimensions display and how blocks behave when inserted. Get this wrong at the start and every imported DWG will arrive scaled incorrectly. Always check UNITS before opening a drawing from an external source. INSERT (also I) - Brings blocks and external references into the drawing. Block insertion scales and rotates based on the prompt sequence. XREF is the same concept but keeps the geometry external so updates propagate. I prefer XREF for site plans and background reference drawings because it prevents file bloat and keeps revision control sane.
OUTLINE and TEXT commands are covered briefly below since they appear frequently in everyday work. TEXT (also T for multiline text) - Places annotated text. MTEXT supports basic formatting, fields, and column layout. SINGLE LINE TEXT (DT) is the older command and creates non-formatted text objects. The reason people mix them up is that MTEXT renders differently during plotting depending on the text style assigned. Always check your text style before annotating a sheet that is going to a client. EXPLODE (also X) - Breaks compound objects into their constituent parts. Polylines become individual lines and arcs. Blocks become individual objects. Hatches become pattern definitions. Use this sparingly. Exploding a block destroys the reference that makes it useful later. I keep a mental note of which blocks I should unblock before editing because once exploded, recovery requires either undo or reopening the file.
MEASURE and DIVIDE - Place points or blocks at equal intervals along an object. MEASURE spaces objects at a specified distance. DIVIDE spaces them into a specified number of segments. Useful for spacing lighting fixtures, columns, or railings. The points are invisible by default. Change the point style with DDPTYPE or the style variable PDMODE to make them visible. ARRAY (also AR) - Creates polygonal, rectangular, or path arrays. Rectangular array is the most common. Specify rows, columns, and spacing. Path array places copies along a curve. Object array replaces the old ARRAY command and offers live preview with editable grips. The gap is calculated from center to center, not edge to edge, which catches people out when they expect clearance between objects. REGION and UNION, SUBTRACT, INTERSECT - Boolean operations on closed shapes. Convert closed polylines or circles into regions, then combine or subtract them. This is how you create custom floor plate geometries without tracing. The objects must be coplanar and closed. If a region fails to create, there is a gap in your boundary smaller than your epsilon tolerance. Increase the tolerance or find the gap with ZOOM EXTENTS and a close inspection.
VIEW, VPOINT, and 3D navigation commands - Switching between 2D and 3D workspace changes the command context. Some commands disappear or behave differently. NAVIGATE with the mouse wheel for orbit, pan, and zoom. If you are working in 3D and the view feels locked, type CAMERADISTANCE or switch to a standard view with VIEWLIST. Isometric views are predictable. Perspective views require a camera object. SOLID, 3DFACE, and 3DSOLID - Basic 3D primitives. BOX, CYLINDER, SPHERE, WEDGE, TORUS, CONE, PYRAMID. These create actual solid geometry that supports boolean operations and mass property calculations. Not just visual representation. You can run MASSPROP on a 3DSOLID and get volume, surface area, and centroid coordinates directly. SECTIONPLANE and SECTION - Creates cut sections through 3D models. Useful for generating elevation views from a plan without manually redrawing. The section boundary can be moved and rotated after creation. Section objects are annotation-aware and will update when the model changes.
Most of the commands above cover ninety percent of daily drafting work. The remaining ten percent involves specialized toolsets for mechanical, electrical, or architectural design. Those are separate licenses and add-on modules. If your office has the base product only, the commands above are your entire toolkit. The real bottleneck is not knowing which command to type. It is knowing when not to use a command and using the right workflow instead. Moving geometry by selecting individual lines rather than a polyline costs three times as long. Dimensioning before organizing layers causes rework when layers get renamed. Plotting from model space instead of a layout viewport introduces scaling headaches that compound across every sheet. I keep the command line visible at all times. Hiding it saves screen space but costs time in lookup. Learning the abbreviations takes about a week of consistent use and then becomes involuntary. The full command names are available if you type them out, but the shortcuts are what make the difference between a productive session and a frustrating one.
If you are starting fresh, practice with a real drawing rather than tutorial exercises. Open an existing DWG, pick a room or a detail, and reconstruct it from scratch using only the commands listed here. The errors you make during that exercise teach you more than any reference list ever will.
