What 5e Rules Are the Most Important to Follow in a Campaign, and Which Ones Do I Like Letting Slide?

I remember the first time I sat behind a table with a group of friends who thought they were the masters of the game. We had just rolled a spell‑casting check for a wizard named Tharion, who was trying to turn a goblin into a frog. The DM—me, in that case—had told the players to “roll a saving throw.” The wizard flopped a 4, the goblin looked very sad, and then everyone laughed because the rule book says you must roll a d20 + DC. The joke was on us; we’d all forgotten the safety net of the rules.

That night taught me two things: first, that rules are the scaffolding that keeps our stories from collapsing; second, that some rules are more important than others. Below I’ll lay out which 5e mechanics deserve your full attention and which ones you can afford to bend when the narrative calls for it. Grab a mug of ale, roll a few dice, and let’s dive in.

The Core Rules That Keep Your Table from Falling Apart

The Combat Framework

• Turn Order: Initiative is the backbone of every encounter. Skipping it or letting players skip turns without consequence can turn a tense skirmish into a free‑form brawl.
• Attack Rolls & Armor Class: Remember, the DM decides whether an attack hits before you roll the damage. If you let your party decide “yes” or “no,” you’re giving them too much agency and losing narrative control.
• Saving Throws: Every spell, trap, or environmental hazard should have a saving throw. It gives players a chance to influence outcomes instead of being pure numbers.

Ability Checks & Skill Usage

• Use the Skills: Don’t ignore the skill list when a player offers a creative solution. The skill is there for a reason; if you can’t find an appropriate check, consider adding one.
• The “Any Other Effect” Rule: Whenever the DM says “the effect could be anything,” it’s time to ask what the players intend and guide them toward an existing mechanic.

Spellcasting & Magic Items

• Spell Slots as Resources: Treat spell slots like a finite resource. If you let characters waste them on trivial effects, they’ll run out during crucial moments.
• Item Activation: Most magic items have a clear activation cost or condition. Respect those rules; otherwise the item becomes a “free lunch” that disrupts balance.

Rules I Like to Let Slip When the Story Demands It

The Dice‑Roll‑Only Approach

• Narrative Damage: Sometimes you want to say, “You slam the goblin’s head into the wall; it’s a crushing blow.” You can roll for damage but describe the action in vivid terms. Players love when their actions feel consequential.
• Rounding Rules: In tight fights, I’ll let players round up or down if it keeps the story moving. A 1‑point difference rarely changes the outcome of an epic showdown.

The “Optional” Rules

• Critical Success/Failure: Many groups ignore the 20/1 rule for dramatic effect. If you’re running a horror campaign, you might let a critical failure trigger a terrifying event even if the check is high.
• Falling Damage: When a character falls into a pit of lava, I’ll sometimes skip the falling damage calculation and just say they’re engulfed in flames—because the narrative beats the math.

Player‑Created Content

• Home‑Brew Spells: I allow players to create spells that fit their character’s story, as long as the power level is roughly equivalent to an existing spell. It keeps them invested and avoids the “homebrew flood” problem.
• Custom Items: If a player wants a unique artifact, I’ll give it one or two stat blocks but let them decide how it looks. The DM should still keep an eye on balance.

How to Decide What to Keep Strict and What to Flex

Ask Yourself These Questions

• Does the rule affect the outcome of the story? If yes, keep it tight.
• Is the rule a safety net for players or a tool for narrative? The former deserves strictness; the latter can be flexible.
• Will bending the rule give an unfair advantage to one party? Avoid that at all costs.

A Mini Story: The Goblin King’s Pact

I once had a group where the wizard, Tharion, tried to negotiate with a goblin king. The DM said the goblin would attempt a Persuasion check. Instead of rolling, the wizard whispered an offer that was so clever it made the goblin laugh. The DM rolled a 17 (DC 15) and decided the goblin accepted. The rule could have been broken—if the players had tried to negotiate without a roll—but the story felt richer because the DM let the narrative take priority.

Common Mistakes I’ve Seen at the Table

• Skipping Initiative: Players think it’s a waste of time, but it creates tension and structure.
• Over‑lawyering Spells: Insisting on every spell having an exact effect can stifle creativity.
• Forgetting Saving Throws: A spell that never gives a chance to resist feels unfair.

Quick Tips Checklist for DMs

• [ ] Keep Initiative, Attack Rolls, and Saving Throws strict.
• [ ] Allow creative skill use; don’t dismiss player ideas.
• [ ] Flex damage descriptions when they add flavor.
• [ ] Balance home‑brew content by comparing to existing stats.
• [ ] Always ask: “What is the narrative impact?” before bending a rule.

A Mini Encounter You Can Drop In

The Whispering Vault

Your party enters an ancient vault rumored to hold a lost relic. As they step forward, a sudden silence falls. The walls glow with runes that whisper in voices only the Intelligence check can understand.

• Each player rolls an Intelligence (Arcana) check. If they fail by 5 or more, they hear the vault’s curse—lose a level of spell slots for the next day.
• If any player succeeds, the vault grants them one free spell slot to use later in the campaign.

This encounter uses the core rules (skill checks and consequences) but lets you tell an atmospheric story.

From Behind the Screen: Why Rules Matter

When I first started DMing, I was terrified of breaking a rule. The fear that a single mis‑roll could ruin a campaign made me rigid. Over time, I learned that rules are guides, not cages. They help us keep balance and fairness while giving us room to improvise.

Final Thought

Rules are your toolbox; narrative is the painting. Keep the structure tight where it matters, and let the brush strokes flow elsewhere. Your players will thank you when they feel both safe and free to shape their destiny.

“If you can’t decide on a rule, just roll a d20 and trust the outcome.” – A cynical DM’s favorite mantra.

Till next time, watch your torches and check for traps. And remember: every great adventure starts with a single roll of the dice.

Question for You: Which rule do you think is most essential to keep strict, and which one would you gladly bend in your next campaign?