diff --git a/README.md b/README.md
index 852a5da..5896bc6 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,7 @@ Add the above line to your favorite shell configuration file (e.g. `~/.bashrc`,
 
 - [`ach`](ach): Add the last commit hash to a given file (`.git-blame-ignore-revs` file by default).
 - [`chdirx`](chdirx): Add `+x` permission to all executable files (that start with `#!`) in the given directory.
+- [`em_`](em_) / [`en_`](en_): Copy typographic dashes to the system clipboard. `em_` copies em dash (—, Unicode U+2014), `en_` copies en dash (–, Unicode U+2013).
 - [`gcfixup`](gcfixup): Create a fixup commit and automatically rebase with autosquash.
 - [`git-shed`](git-shed): Identify and remove merged & stale branches with respect to a target branch.
 - [`how-big`](how-big): Show the size of the given directory.
diff --git a/_mnn b/_mnn
new file mode 100755
index 0000000..16f7141
--- /dev/null
+++ b/_mnn
@@ -0,0 +1,195 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+SCRIPT_NAME=$(basename "$0")
+
+# Trap handlers for error recovery
+trap 'cleanup_on_error' ERR
+trap 'cleanup_on_exit' EXIT
+
+cleanup_on_error() {
+	local exit_code=$?
+	echo "Error: Script failed with exit code $exit_code" >&2
+	exit $exit_code
+}
+
+cleanup_on_exit() {
+	# Cleanup logic if needed
+	:
+}
+
+# Detect platform
+detect_platform() {
+	case "$(uname -s)" in
+	Darwin*)
+		echo "macos"
+		;;
+	Linux*)
+		if [[ -n "${WAYLAND_DISPLAY:-}" ]]; then
+			echo "wayland"
+		else
+			echo "x11"
+		fi
+		;;
+	CYGWIN* | MINGW* | MSYS*)
+		echo "windows"
+		;;
+	*)
+		echo "unknown"
+		;;
+	esac
+}
+
+# Select clipboard command based on platform
+select_clipboard_command() {
+	local platform=$1
+	case "$platform" in
+	macos)
+		if command -v pbcopy >/dev/null 2>&1; then
+			echo "pbcopy"
+		else
+			echo "ERROR:pbcopy not found"
+		fi
+		;;
+	x11)
+		if command -v xclip >/dev/null 2>&1; then
+			echo "xclip -selection clipboard"
+		elif command -v xsel >/dev/null 2>&1; then
+			echo "xsel --clipboard"
+		else
+			echo "ERROR:xclip or xsel not found"
+		fi
+		;;
+	wayland)
+		if command -v wl-copy >/dev/null 2>&1; then
+			echo "wl-copy"
+		else
+			echo "ERROR:wl-copy not found"
+		fi
+		;;
+	windows)
+		if command -v clip.exe >/dev/null 2>&1; then
+			echo "clip.exe"
+		else
+			echo "ERROR:clip.exe not found"
+		fi
+		;;
+	*)
+		echo "ERROR:unsupported platform"
+		;;
+	esac
+}
+
+# Select dash character based on script name
+select_dash() {
+	case "$SCRIPT_NAME" in
+	en_)
+		echo "–" # en dash U+2013
+		;;
+	em_)
+		echo "—" # em dash U+2014
+		;;
+	*)
+		echo "ERROR:invalid script name"
+		;;
+	esac
+}
+
+# Display help message
+usage() {
+	cat <<EOF
+Usage: $SCRIPT_NAME [OPTIONS]
+
+Copies $(if [[ "$SCRIPT_NAME" == "en_" ]]; then echo "en dash"; else echo "em dash"; fi) (Unicode U+$(if [[ "$SCRIPT_NAME" == "en_" ]]; then echo "2013"; else echo "2014"; fi)) to the system clipboard.
+
+Options:
+  -h, --help    Show this help message and exit.
+
+Examples:
+  $SCRIPT_NAME           # Copy $(if [[ "$SCRIPT_NAME" == "en_" ]]; then echo "en dash (–)"; else echo "em dash (—)"; fi) to clipboard
+
+Note: This script must be invoked as 'en_' or 'em_'. The dash character
+copied is determined by the command name used.
+EOF
+	exit 0
+}
+
+# Main execution
+main() {
+	# Parse command-line arguments
+	if [[ $# -gt 0 ]]; then
+		case "$1" in
+		-h | --help)
+			usage
+			;;
+		*)
+			echo "Error: Unknown option '$1'" >&2
+			echo "Run '$SCRIPT_NAME --help' for usage information." >&2
+			exit 2
+			;;
+		esac
+	fi
+
+	# Validate script name
+	if [[ "$SCRIPT_NAME" == "_mnn" ]]; then
+		echo "Error: This script must be invoked as 'en_' or 'em_'" >&2
+		exit 1
+	fi
+
+	# Select dash character
+	local dash
+	dash=$(select_dash)
+	if [[ "$dash" == ERROR:* ]]; then
+		echo "Error: This script must be invoked as 'en_' or 'em_'" >&2
+		exit 1
+	fi
+
+	# Detect platform
+	local platform
+	platform=$(detect_platform)
+	if [[ "$platform" == "unknown" ]]; then
+		local uname_output
+		uname_output=$(uname -s)
+		echo "Error: Unsupported platform: $uname_output. This script supports macOS, Linux (X11/Wayland), and Windows." >&2
+		exit 1
+	fi
+
+	# Select clipboard command
+	local clipboard_cmd
+	clipboard_cmd=$(select_clipboard_command "$platform")
+	if [[ "$clipboard_cmd" == ERROR:* ]]; then
+		case "$platform" in
+		macos)
+			echo "Error: Clipboard tool 'pbcopy' not found. This should be available on macOS." >&2
+			;;
+		x11)
+			echo "Error: Clipboard tool 'xclip' or 'xsel' not found. Please install xclip (preferred) or xsel." >&2
+			;;
+		wayland)
+			echo "Error: Clipboard tool 'wl-copy' not found. Please install wl-clipboard package." >&2
+			;;
+		windows)
+			echo "Error: Clipboard tool 'clip.exe' not found. This should be available on Windows." >&2
+			;;
+		esac
+		exit 1
+	fi
+
+	# Copy to clipboard
+	if [[ "$platform" == "windows" ]]; then
+		# Windows echo doesn't support -n flag
+		echo "$dash" | $clipboard_cmd || {
+			echo "Error: Failed to copy to clipboard: $?" >&2
+			exit 1
+		}
+	else
+		# Unix-like systems support echo -n
+		echo -n "$dash" | $clipboard_cmd || {
+			echo "Error: Failed to copy to clipboard: $?" >&2
+			exit 1
+		}
+	fi
+}
+
+main "$@"
diff --git a/em_ b/em_
new file mode 120000
index 0000000..d721f44
--- /dev/null
+++ b/em_
@@ -0,0 +1 @@
+_mnn
\ No newline at end of file
diff --git a/en_ b/en_
new file mode 120000
index 0000000..d721f44
--- /dev/null
+++ b/en_
@@ -0,0 +1 @@
+_mnn
\ No newline at end of file
diff --git a/tests/_mnn.bats b/tests/_mnn.bats
new file mode 100755
index 0000000..0f6e725
--- /dev/null
+++ b/tests/_mnn.bats
@@ -0,0 +1,303 @@
+#!/usr/bin/env bats
+
+bats_require_minimum_version 1.5.0
+
+load 'test_helper'
+
+# Helper function to get clipboard content (platform-specific)
+get_clipboard() {
+	case "$(uname -s)" in
+	Darwin*)
+		pbpaste 2>/dev/null || echo ""
+		;;
+	Linux*)
+		if [[ -n "${WAYLAND_DISPLAY:-}" ]]; then
+			wl-paste 2>/dev/null || echo ""
+		else
+			xclip -selection clipboard -o 2>/dev/null || xsel --clipboard --output 2>/dev/null || echo ""
+		fi
+		;;
+	CYGWIN* | MINGW* | MSYS*)
+		# Windows clipboard reading is complex, skip for now
+		echo ""
+		;;
+	*)
+		echo ""
+		;;
+	esac
+}
+
+# Helper to check if clipboard tool is available
+has_clipboard_tool() {
+	case "$(uname -s)" in
+	Darwin*)
+		command -v pbcopy >/dev/null 2>&1
+		;;
+	Linux*)
+		if [[ -n "${WAYLAND_DISPLAY:-}" ]]; then
+			command -v wl-copy >/dev/null 2>&1
+		else
+			command -v xclip >/dev/null 2>&1 || command -v xsel >/dev/null 2>&1
+		fi
+		;;
+	CYGWIN* | MINGW* | MSYS*)
+		command -v clip.exe >/dev/null 2>&1
+		;;
+	*)
+		return 1
+		;;
+	esac
+}
+
+@test "_mnn: script has valid bash syntax" {
+	bash -n "$SCRIPTS_DIR/_mnn"
+}
+
+# Phase 2: Foundational tests
+@test "_mnn: script name detection works" {
+	# Test that script detects its own name
+	run "$SCRIPTS_DIR/_mnn"
+	[ "$status" -ne 0 ]
+	assert_output_contains "must be invoked as 'en_' or 'em_'"
+}
+
+# Phase 3: User Story 1 - En Dash tests
+@test "en_: copies en dash to clipboard" {
+	skip_if_no_clipboard_tool
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+
+	local clipboard_content
+	clipboard_content=$(get_clipboard)
+	[ "$clipboard_content" = "–" ]
+}
+
+@test "en_: overwrites previous clipboard content" {
+	skip_if_no_clipboard_tool
+
+	# Put something in clipboard first
+	case "$(uname -s)" in
+	Darwin*)
+		echo -n "test content" | pbcopy
+		;;
+	Linux*)
+		if [[ -n "${WAYLAND_DISPLAY:-}" ]]; then
+			echo -n "test content" | wl-copy
+		else
+			echo -n "test content" | xclip -selection clipboard 2>/dev/null || echo -n "test content" | xsel --clipboard 2>/dev/null
+		fi
+		;;
+	CYGWIN* | MINGW* | MSYS*)
+		echo "test content" | clip.exe
+		;;
+	esac
+
+	# Run en_ and verify it overwrote
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+
+	local clipboard_content
+	clipboard_content=$(get_clipboard)
+	[ "$clipboard_content" = "–" ]
+	[ "$clipboard_content" != "test content" ]
+}
+
+@test "en_: exits with code 0 on success" {
+	skip_if_no_clipboard_tool
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+}
+
+# Phase 4: User Story 2 - Em Dash tests
+@test "em_: copies em dash to clipboard" {
+	skip_if_no_clipboard_tool
+	run "$SCRIPTS_DIR/em_"
+	[ "$status" -eq 0 ]
+
+	local clipboard_content
+	clipboard_content=$(get_clipboard)
+	[ "$clipboard_content" = "—" ]
+}
+
+@test "em_: overwrites previous clipboard content" {
+	skip_if_no_clipboard_tool
+
+	# Put something in clipboard first
+	case "$(uname -s)" in
+	Darwin*)
+		echo -n "test content" | pbcopy
+		;;
+	Linux*)
+		if [[ -n "${WAYLAND_DISPLAY:-}" ]]; then
+			echo -n "test content" | wl-copy
+		else
+			echo -n "test content" | xclip -selection clipboard 2>/dev/null || echo -n "test content" | xsel --clipboard 2>/dev/null
+		fi
+		;;
+	CYGWIN* | MINGW* | MSYS*)
+		echo "test content" | clip.exe
+		;;
+	esac
+
+	# Run em_ and verify it overwrote
+	run "$SCRIPTS_DIR/em_"
+	[ "$status" -eq 0 ]
+
+	local clipboard_content
+	clipboard_content=$(get_clipboard)
+	[ "$clipboard_content" = "—" ]
+	[ "$clipboard_content" != "test content" ]
+}
+
+@test "em_: exits with code 0 on success" {
+	skip_if_no_clipboard_tool
+	run "$SCRIPTS_DIR/em_"
+	[ "$status" -eq 0 ]
+}
+
+# Phase 5: User Story 3 - Cross-platform tests
+@test "en_: works on macOS with pbcopy" {
+	[[ "$(uname -s)" == "Darwin" ]] || skip "Not macOS"
+	command -v pbcopy >/dev/null 2>&1 || skip "pbcopy not available"
+
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+}
+
+@test "en_: works on Linux X11 with xclip" {
+	[[ "$(uname -s)" == "Linux" ]] || skip "Not Linux"
+	[[ -z "${WAYLAND_DISPLAY:-}" ]] || skip "Not X11"
+	command -v xclip >/dev/null 2>&1 || skip "xclip not available"
+
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+}
+
+@test "en_: falls back to xsel when xclip unavailable on X11" {
+	[[ "$(uname -s)" == "Linux" ]] || skip "Not Linux"
+	[[ -z "${WAYLAND_DISPLAY:-}" ]] || skip "Not X11"
+	command -v xsel >/dev/null 2>&1 || skip "xsel not available"
+	# Only test if xclip is not available
+	command -v xclip >/dev/null 2>&1 && skip "xclip is available"
+
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+}
+
+@test "en_: works on Linux Wayland with wl-copy" {
+	[[ "$(uname -s)" == "Linux" ]] || skip "Not Linux"
+	[[ -n "${WAYLAND_DISPLAY:-}" ]] || skip "Not Wayland"
+	command -v wl-copy >/dev/null 2>&1 || skip "wl-copy not available"
+
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+}
+
+@test "en_: works on Windows with clip.exe" {
+	[[ "$(uname -s)" =~ ^(CYGWIN|MINGW|MSYS) ]] || skip "Not Windows"
+	command -v clip.exe >/dev/null 2>&1 || skip "clip.exe not available"
+
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+}
+
+@test "_mnn: shows error for unsupported platform" {
+	# This is hard to test without mocking uname, but we can test the error message format
+	run "$SCRIPTS_DIR/_mnn"
+	[ "$status" -ne 0 ]
+	assert_output_contains "must be invoked as 'en_' or 'em_'"
+}
+
+@test "_mnn: shows error when clipboard tool missing" {
+	# This would require mocking command -v, which is complex
+	# For now, we test that the script handles missing tools gracefully
+	# by checking it doesn't crash
+	skip "Requires mocking command availability"
+}
+
+# Phase 6: User Story 4 - Help tests
+@test "en_: --help displays help message" {
+	run "$SCRIPTS_DIR/en_" --help
+	[ "$status" -eq 0 ]
+	assert_output_contains "Usage:"
+	assert_output_contains "en dash"
+	assert_output_contains "U+2013"
+}
+
+@test "en_: -h displays help message" {
+	run "$SCRIPTS_DIR/en_" -h
+	[ "$status" -eq 0 ]
+	assert_output_contains "Usage:"
+	assert_output_contains "en dash"
+}
+
+@test "em_: --help displays help message" {
+	run "$SCRIPTS_DIR/em_" --help
+	[ "$status" -eq 0 ]
+	assert_output_contains "Usage:"
+	assert_output_contains "em dash"
+	assert_output_contains "U+2014"
+}
+
+@test "em_: -h displays help message" {
+	run "$SCRIPTS_DIR/em_" -h
+	[ "$status" -eq 0 ]
+	assert_output_contains "Usage:"
+	assert_output_contains "em dash"
+}
+
+@test "en_: help option exits with code 0" {
+	run "$SCRIPTS_DIR/en_" --help
+	[ "$status" -eq 0 ]
+}
+
+# Phase 7: Polish - Error handling tests
+@test "_mnn: shows error when invoked directly" {
+	run "$SCRIPTS_DIR/_mnn"
+	[ "$status" -eq 1 ]
+	assert_output_contains "must be invoked as 'en_' or 'em_'"
+}
+
+@test "en_: shows error for invalid option" {
+	run "$SCRIPTS_DIR/en_" --invalid
+	[ "$status" -eq 2 ]
+	assert_output_contains "Unknown option"
+}
+
+@test "en_: error messages go to stderr" {
+	run "$SCRIPTS_DIR/en_" --invalid
+	[ "$status" -eq 2 ]
+	# stderr should contain error, stdout should be empty or minimal
+	[ -n "$output" ]
+}
+
+@test "_mnn: follows set -euo pipefail pattern" {
+	# Check that script has set -euo pipefail
+	grep -q "set -euo pipefail" "$SCRIPTS_DIR/_mnn"
+}
+
+@test "en_: multiple sequential invocations overwrite clipboard" {
+	skip_if_no_clipboard_tool
+
+	# Run en_ first
+	run "$SCRIPTS_DIR/en_"
+	[ "$status" -eq 0 ]
+
+	local clipboard1
+	clipboard1=$(get_clipboard)
+	[ "$clipboard1" = "–" ]
+
+	# Run em_ second - should overwrite
+	run "$SCRIPTS_DIR/em_"
+	[ "$status" -eq 0 ]
+
+	local clipboard2
+	clipboard2=$(get_clipboard)
+	[ "$clipboard2" = "—" ]
+	[ "$clipboard2" != "$clipboard1" ]
+}
+
+# Helper function to skip tests if clipboard tool is not available
+skip_if_no_clipboard_tool() {
+	has_clipboard_tool || skip "Clipboard tool not available on this platform"
+}