D&D 5e 2024 DM Primer

Your Complete Guide to Running D&D with the New Rules

Quick Start: What You NEED to Know Right Now

Your Campaign Context

Campaign: Horror anthology (Librus Nocturnum)
Players: 4-5 (Cieth, Dial, Skykros, Yrene, Baji)
Session 0: Complete ✓
Player Interests: Problem-solving, roleplay, mystery, high fantasy, action
Your Custom Rules: Proficiency as damage die, permadeath, session advantages

The Three Things That Matter Most

Keep It Moving: If something takes more than 30 seconds to look up, make a ruling and check later
Focus on Fun: Rules serve the story, not the other way around
You're Not the Enemy: You provide challenges, not opposition to defeat

Part 1: Key 2024 Rule Changes (From 2014)

Combat & Actions

Grappling Simplified

Now uses an Unarmed Strike (Attack action)
Target makes STR or DEX save vs DC 8 + prof + STR mod
Grappled condition: Speed 0, disadvantage on attacks NOT against grappler
Move grappled creature at half speed

Two-Weapon Fighting

Part of the Attack action now (not bonus action)
Light property lets you make one extra attack
Can draw/stow both weapons as part of attack

Opportunity Attacks

Now triggered by leaving a creature's reach (not just moving away)
Disengage prevents for entire turn

Conditions Updated

Exhaustion: Now -2 per level to all d20 tests and Speed (simpler!)
Surprised: Not a condition anymore, just disadvantage on Initiative
Unconscious: Explicitly drops anything held

Spellcasting

Spell Preparation

All casters now prepare spells = spell mod + class level
Ritual casting doesn't require preparation (if you have the feature)

Spell Lists Reorganized

Arcane: Artificer, Bard, Sorcerer, Warlock, Wizard
Divine: Cleric, Paladin
Primal: Druid, Ranger

Concentration

Incapacitated always breaks concentration (including stunned)

Counterspell/Dispel Magic

Always requires ability check now (no auto-success)
DC = 10 + spell's level

Character Creation

Backgrounds Give Feats

Every background provides an Origin feat at 1st level
Ability Score Increases come from backgrounds now, not species

Species (Races) Changes

No ability score bonuses (moved to backgrounds)
Size can be Small or Medium (player choice for most)
Lifespans specified but no mechanical impact

Feats at ASI Levels

Can always take a feat instead of ASI
General feats available to all
Some feats have level prerequisites (4th, 8th, etc.)

Rest & Recovery

Short Rest

Still 1 hour
Spend Hit Dice to heal
Some features recharge

Long Rest

Regain all HP
Regain half total Hit Dice (round up)
Regain all spent spell slots
Must have 1+ HP to benefit

D20 Tests

New Terminology

"D20 Test" = any d20 roll (attack, save, check)
Advantage/Disadvantage can apply to any D20 Test
Some features affect "all D20 Tests"

Ability Check DCs (Reference)

Very Easy: 5
Easy: 10
Medium: 15
Hard: 20
Very Hard: 25
Nearly Impossible: 30

Part 2: Essential DM Mechanics

Running Your Session

The Basic Loop

Describe the Situation (3 sentences max)
Let Players Talk (what do you do?)
Resolve Actions (rolls, roleplay, or it just happens)
Back to Step 1

Time Management

One Hour of Play = 3 "Things"

Explore a location
Talk to an NPC
Solve a puzzle
Survive a trap
Easy combat

Tough fights = 2-3 things, tense negotiations = full hour

Combat Management

Initiative Options

Method 1: Roll Every Time (Traditional)

Roll d20 + Initiative modifier
Reroll ties or use DEX scores

Method 2: Fixed Initiative (Faster)

Use 10 + Initiative modifier
Advantage = +5, Disadvantage = -5
No rolling needed

Tracking HP

Option A: Track damage dealt (easier math)

Ogre: 0→15→28→45→59 (dead at 59 HP)

Option B: Track HP remaining (traditional)

Ogre: 59→44→31→14→0

Keep Combat Moving

Bloodied: Describe visible wounds at half HP
Nearly Dead: "One more good hit will drop it"
Skip the Slog: Kill at 0-5 HP remaining
Enemies Flee: When clearly losing
Terrain Changes: Destroy cover, add hazards

Quick NPC Creation

Pick 1-2 personality traits
Choose a voice/mannerism
Give them a want/need
Done!

STR: Intimidation through force
DEX: Sleight of Hand during conversation
CON: Drinking contests
INT: Debate, riddles, recall information
WIS: Insight, detect lies
CHA: Standard social skills

Horror Campaign Specific

Building Tension

Describe using multiple senses (smell rot, hear creaking)
Let silence build (count to 3 before revealing)
Use exhaustion and resource depletion
Make rests dangerous

Librus Nocturnum Tips

Each adventure is self-contained (good for learning)
Start with lower-level adventures
Use atmospheric music/sounds
Dim lights during play if possible

Part 3: Your First Real Session Checklist

Before the Session (30 min prep)

Must Have

Read the adventure you're running
Note 3 key encounters (likely to happen)
Have monster stats ready (bookmark or print)
Load maps in Foundry
Review any PC backstory connections

Nice to Have

Prepare NPC voices/mannerisms
Queue atmospheric music
Pre-roll some Initiative

Starting the Session

First 10 Minutes

Recap: "Last time..." (let players help)
Set the Scene: Where are they now?
Ask: "What are you doing?"

During Play

When Players Do Something:

Can they just do it? → It happens
Is there risk/obstacle? → Roll for it
Is it impossible? → Tell them

When to Call for Rolls:

Failure has consequences
Success isn't guaranteed
Time pressure exists

DC Quick Reference:

Easy (10): Most people could do it
Medium (15): Requires skill/effort
Hard (20): Impressive achievement

Combat Round-by-Round

Round 1

Describe the scene
Roll/assign Initiative
Telegraph enemy abilities

Each Turn

"[Name], you're up. What do you do?"
Resolve their action
Describe results narratively
"Next is [name]"

Keep It Fast

30-second rule for decisions
Roll attack and damage together
Group identical monsters

Ending the Session

Last 15 Minutes

Find a natural stopping point
Award inspiration for good RP
Ask: "What was your favorite moment?"
Remind about next session poll

Part 4: Quick References

Conditions You'll Use Most

Grappled

Speed becomes 0
Disadvantage on attacks (except vs grappler)

Prone

Attacks within 5ft: Advantage
Attacks beyond 5ft: Disadvantage
Half speed to stand

Frightened

Disadvantage on checks/attacks while seeing source
Can't willingly move closer

Exhaustion (NEW!)

-2 per level to d20 rolls and Speed
Level 10 = death

Actions in Combat

Attack: Make weapon/spell attack

Dash: Double movement

Dodge: Attackers have disadvantage

Help: Give ally advantage

Hide: Dexterity (Stealth) check

Ready: Prepare triggered action

Search: Perception/Investigation

Common DM Rulings

Can they see in darkness?

Darkvision: See in dim light as bright (no color)
Without: Disadvantage on sight-based checks

How far can they jump?

Long Jump: STR score in feet (with 10ft run)
High Jump: 3 + STR mod feet (with 10ft run)

How long can they hold breath?

1 + CON mod minutes (minimum 30 seconds)

Fall damage?

1d6 per 10 feet (max 20d6)

Part 5: Your Specific Campaign Notes

Your House Rules (From Session 0)

Proficiency = Damage Die: Instead of flat damage
Session Benefits: 1 Advantage (before roll) + 1 Mulligan (after roll)
Permadeath: No resurrection magic
Milestone Leveling: No XP tracking

Your Players' Interests

Combat: Baji, Skykros
Roleplay: Dial, Cieth
Problem-Solving: Yrene, Dial
Mystery: Dial
Criminal Activity: Sky, Baji (work this in!)

Managing Your Table

For Dial (roleplay-heavy):

Give NPCs memorable personalities
Create moral dilemmas
Let them lead social encounters

For Baji/Sky (action/criminal):

Include heist elements
Add chase scenes
Provide combat options

For Yrene (goals/quests):

Clear objectives
Progress tracking
Meaningful rewards

Librus Nocturnum Structure

13 adventures (levels 0-12)
Each is 1-3 sessions
Start with lower levels to learn
Horror theme throughout

Part 6: Common Problems & Solutions

"My Players Are Too Cautious"

Add time pressure (ritual completes at midnight)
Make inaction have consequences
Reward bold action with inspiration

"Combat Is Too Slow"

Use average damage for monsters
Group monster initiatives
Set turn timer (2 minutes)
Say "Next up is [name]" during current turn

"Players Aren't Engaged"

Call on quiet players directly
Give each PC a spotlight moment
Connect events to backstories
Take a break and check in

"I Don't Know a Rule"

Make a quick ruling
Note it for later
Look it up after session
Be consistent going forward

"Players Argue With Rulings"

"We'll go with this for now and discuss after"
Set expectation: DM rulings are final in-moment
Allow one appeal per session
Encourage looking up rules during breaks

Part 7: Resources & References

Your Extracted Books

PHB 2024: ~/docs/dnd/phb-2024/
DMG 2024: ~/docs/dnd/dmg-2024/

Key Sections to Bookmark

PHB Essentials:

Actions: phb-2024/016-actions/
Combat: phb-2024/032-combat/
Conditions: phb-2024/037-conditions/
Spells: phb-2024/027-spells/

DMG Essentials:

Running the Game: dmg-2024/001-running-the-game/
DM Toolbox: dmg-2024/008-dms-toolbox/
Magic Items: dmg-2024/011-magic-items/
Treasure: dmg-2024/009-treasure/

Quick Lookups During Play

Keep conditions list handy
Bookmark common spells
Have NPC name generator ready
Print common monster stats

Your Next Steps

This Week

Read one Librus Nocturnum adventure fully
Prepare that adventure in Foundry
Create 3 generic NPCs (name, trait, voice)
Practice describing 3 locations (3 sentences each)

Before Next Session

Review player character sheets
Note their AC, passive Perception, and key abilities
Prepare opening scene description
Have backup encounters ready

After Each Session

Take notes on what worked/didn't
Ask players for feedback
Prep next session based on where they ended
Celebrate what went well!

Remember: You've Got This!

You already have:

Engaged players who showed up to Session 0
Foundry set up and working
Horror adventures ready to run
This guide and the full rulebooks

The secret: Your players WANT you to succeed. They're on your side. If you're enthusiastic and fair, they'll forgive any mistakes.

Start small: Run one encounter. Then another. Before you know it, you'll have run entire sessions.

Most importantly: Have fun! If you're enjoying yourself, your players will too.

"The DM is the player who prepares, presents, and presides over the game's world and story." - DMG 2024

You're not just running a game—you're facilitating shared storytelling. Welcome to the DM's chair!