Removing Em-Dashes from Prose: Alternatives and Implementation in Stop-Slop

Remove em-dashes from AI-generated prose to eliminate predictable punctuation patterns and enforce clearer syntax using commas, periods, or semicolons instead.

The Stop-Slop skill is a collection of editorial rules designed to strip predictable AI "tells" from text. According to the source code in hardikpandya/stop-slop, removing em-dashes is a core requirement for producing human-like writing that avoids formulaic rhythms.

Why Remove Em-Dashes? The Core Rationale

The Stop-Slop skill treats em-dashes as a stylistic crutch that signals machine-generated text. According to SKILL.md and references/structures.md, the reasoning follows four specific principles:

• Predictability — Em-dashes create visual cues that signal pauses or asides. AI models frequently lean on this punctuation to mimic human "thought trails," creating recognizable patterns that readers associate with synthetic text.

• Clarity and Flow — Overuse fragments sentences into "staccato" rhythms. By banning em-dashes, the skill forces writers to construct natural clause structures that improve readability.

• Consistency — Enforcing a single punctuation style reduces variation that AI models exploit to produce formulaic outputs.

• Simplification for LLMs — When supplied as a system prompt, fewer punctuation tokens mean the model has less room to hide filler behind complex punctuation flourishes.

In SKILL.md, Rule 6 – Vary rhythm explicitly states: "No em dashes." The references/structures.md file expands this under Rule 25 – Rhythm Patterns: "Em-dashes – Remove. Use commas or periods. No em dashes at all."

Alternatives to Em-Dashes in Prose

When removing em-dashes from prose, the Stop-Slop skill recommends specific substitutions based on the grammatical function of the original dash:

Independent clause separation — Replace em-dashes separating two standalone thoughts with a period or semicolon.

Original: "Speed, quality, cost—pick two."
Revised:  "Speed, quality, cost. Pick two."

Cause-and-effect linking — Substitute conjunctions or semicolons when the dash implies a relationship between statements.

Original: "The data tells us—our users love it."
Revised:  "The data tells us; our users love it."

Justification clauses — Rewrite as a single sentence with explicit connecting words.

Original: "We must act now—there's no time to waste."
Revised:  "We must act now because there's no time to waste."

Afterthoughts — Use periods for emphasis or parentheses for incidental information.

Original: "He was late—again."
Revised:  "He was late (again)."

Modifier lists — Convert to comma-separated lists without the dash.

Original: "She smiled—softly, sincerely."
Revised:  "She smiled softly, sincerely."

These alternatives align with the principle in references/structures.md lines 118-126: prefer direct statements over punctuation-driven flourishes.

Implementation: Applying the Stop-Slop Rule

To enforce the em-dash prohibition programmatically or via prompt engineering, reference the specific rule locations in the repository.

When using Claude or similar LLMs, include the skill rules in the system prompt:

system_prompt = """
You are Claude. Apply the Stop-Slop skill rules (see SKILL.md) to the user text.
Rules include:
- Rule 6 (SKILL.md): No em dashes
- Rule 25 (references/structures.md): Em-dashes – Remove. Use commas or periods.
"""

user_text = "The solution is simple—just restart the server."

# Expected transformation:

# "The solution is simple. Just restart the server."

For manual editing, scan for the Unicode character — (em-dash) or double hyphens -- and apply the substitution patterns above based on sentence structure.

Source Files and Rule Locations

The em-dash prohibition is documented across several files in the repository:

• SKILL.md — Contains Rule 6 – Vary rhythm with the flat prohibition "No em dashes" at lines 26-27.

• references/structures.md — Contains Rule 25 – Rhythm Patterns with detailed removal instructions and alternatives at lines 118-126.

• README.md — Provides high-level overview of the skill's goals, including em-dash removal as part of the anti-slop methodology.

• references/examples.md — Shows before-and-after transformations illustrating how em-dashes are removed in practice.

Summary

• The Stop-Slop skill bans em-dashes in SKILL.md Rule 6 and references/structures.md Rule 25 to prevent predictable AI punctuation patterns.
• Key alternatives include periods for sentence breaks, semicolons for related clauses, and conjunctions for explicit logical connections.
• Removing em-dashes forces clearer sentence architecture and eliminates the "staccato" rhythm common in synthetic text.
• Implementation requires either manual substitution based on grammatical context or automated filtering via system prompts referencing the skill rules.

Frequently Asked Questions

What is the Stop-Slop skill?

The Stop-Slop skill is a system prompt framework hosted in the hardikpandya/stop-slop repository that defines editorial rules for identifying and removing AI-generated text patterns. It provides specific constraints on vocabulary, sentence structure, and punctuation—including the complete prohibition of em-dashes—to produce more naturalistic prose.

Why are em-dashes considered an "AI tell"?

Em-dashes are considered an AI tell because large language models frequently use them to simulate human speech patterns and abrupt thought transitions. According to the Stop-Slop source code in references/structures.md, this creates a recognizable visual rhythm that signals formulaic generation rather than deliberate human craft.

Can I use en-dashes or hyphens instead of em-dashes?

The Stop-Slop rules specifically target the em-dash character (—). While the repository does not explicitly ban en-dashes or hyphens, the Rule 25 guidance in references/structures.md emphasizes replacing em-dash functions with commas or periods rather than substituting alternative dash characters. The goal is structural clarity, not merely character substitution.

How do I detect em-dashes in existing text?

Search for the Unicode character U+2014 (—) or double hyphen sequences (--) depending on the source formatting. In references/structures.md, the skill treats both the visual em-dash and common typewriter approximations as violations requiring replacement with standard sentence punctuation.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}