Gridmonger Manual

Advanced editing


The idea behind selections is simple: you select a number of cells first, then perform some action on them.

All editing actions presented so far have to be invoked from Edit Mode, which is the default operational mode of the program. To make a selection, you need to enter Select (Mark) Mode by pressing M. The cursor will turn into a crosshair, and you will see the list of available actions for manipulating the selection in the status bar.

To add a rectangular area to the selection, hold R and use the movement keys. For simplicity’s sake, you can only use Normal Mode movement keys when working with selections, regardless of the currently active editing mode (WASD Mode, Walk Mode, etc.) Selected cells are tinted pink (in most themes; the actual colour is theme-dependent). To subtract a rectangular area from the current selection, hold S and use the movement keys.

Similarly, you can “draw” the selection or “erase” from it by using the D and E modifier keys with the movement keys, respectively. A selects the whole level (Select All), and U clears the selection (Unselect All).


You can left-click with the mouse to set the cursor location in Select Mode too. This opens up some interesting possibilities, e.g. you can draw selections with the mouse when used in conjunction with the D and E modifiers.

Marking a non-contiguous area in Select Mode

Marking a non-contiguous area in Select Mode

When you’re happy with your selection, it’s time to perform an action on it. C (or Y) copies (yanks) the selected cells into the paste buffer and returns to Edit Mode.

You can paste the contents of the buffer at the current cursor position by pressing P. It is important to note that links are not copied, but you can paste the copied content as many times as you wish. This restriction is necessary to maintain the integrity of the links.

If you press Shift+P, you’ll enter Paste Preview Mode where you can position the selection interactively with the movement keys (usually shown in a light-blue overlay, which is, again, theme-dependent), then perform the paste action by pressing Enter, or cancel it with Esc. Note that you can also switch the current level in Paste Preview Mode.

Positioning the selection in Paste Preview Mode

Positioning the selection in Paste Preview Mode


The contents of the paste buffer is preserved when opening another map file. Although you can only edit a single map at a given time, this enables you to copy-paste whole or partial levels between two maps.

Holding Ctrl in Select Mode will reveal a list of further special actions in the status bar:

Move Ctrl+M

The link-preserving alternative to the copy action: the selected cells will be cut first, then you will be automatically taken into Paste Preview Mode where you can reposition the selection. Note that the move action will leave the contents of the paste buffer intact (it uses a dedicated “move buffer” under the hood).

Erase Ctrl+E

Equivalent of using the erase cell action on the selected cells.

Fill Ctrl+F

Equivalent of using the draw/clear floor action on the selected cells.

Set colour Ctrl+C

Set the floor colour of the selected cells to the current colour.

Surround Ctrl+S

Surround the selected cells with solid walls (you can use this with the select rectangle action to draw rectangular rooms quickly).

Crop Ctrl+R

Crop the level to the bounding box of the selection.

Special level actions

There are a few special actions that operate on the whole level. These can be invoked from Edit Mode.

Resize level

The resize level action, invoked by Ctrl+E, lets you to shrink or expand the dimensions of the current level. You’ll need to select an anchor point for the action. It’s probably easiest to illustrate the role of the anchor point through a few examples:

  • Making the level 2 columns and 3 rows larger using the top-left anchor point will add 2 extra empty columns at the right side of the level, and 3 extra empty rows at the bottom.

  • Making the level 4 columns and 4 rows smaller using the centre anchor point will remove a 2-cell wide “stripe” from around the level.

Nudge level

You can shift the contents of the level around without changing its dimensions with the nudge level action.

Press Ctrl+E to enter Nudge Preview Mode, then use the movement keys to reposition the level’s contents. Accept the changes by pressing Enter, or discard them with Esc.