2e → 5e 2024
A survival guide for AD&D veterans entering the modern era
Quick Reference
The most important "muscle memory" changes. Print this section!
The Most Important Formula
This applies to attacks (vs AC), saves (vs DC), and skill checks (vs DC). Higher is ALWAYS better.
What Happened To...
Familiar 2e concepts and their modern equivalents. Click to expand each one.
THAC0 & Attack Tables → Proficiency bonus + ability modifier
Instead of subtracting from THAC0, you now add your proficiency bonus (+2 to +6 based on level) plus your ability modifier (STR for melee, DEX for ranged). Roll d20, add bonuses, compare to AC. Higher is always better!
Non-Weapon Proficiencies → Skills (with proficiency/expertise)
There are 18 skills in 5e. If you're proficient, add your proficiency bonus to checks. Some classes can get 'expertise' for double proficiency. No more slot-based NWPs!
Weapon Proficiencies → Simple/Martial + Weapon Mastery (2024)
Weapons are now 'Simple' (anyone can use) or 'Martial' (need proficiency). In 5e 2024, martial classes also get Weapon Mastery - special effects when you hit (Topple, Vex, etc).
Saving Throw Categories → 6 ability-based saves
Gone are Paralyzation, Rod/Staff/Wand, Petrification, Breath Weapon, and Spell saves. Now each of the 6 abilities (STR, DEX, CON, INT, WIS, CHA) has its own save. Your class gives you proficiency in 2 of them.
Level Limits for Demihumans → Gone completely
Elves, dwarves, and other species can reach level 20 in any class. No artificial caps!
Class/Race Restrictions → Gone completely
Any species can be any class. Want a halfling barbarian or a half-orc wizard? Go for it!
Ability Score Minimums → Gone completely
No minimum ability scores to be a class. A wizard with 8 INT is legal (though not optimal). Your character, your choice.
Exceptional Strength (18/xx) → Just "18" (scores go to 20, or 22 with items)
No more percentile strength. An 18 is an 18. The normal cap is 20, though some magic items can push you to 22 or higher.
Negative AC → AC 20+ is "very good"
AC 10 is baseline (unarmored, no DEX). Plate armor + shield = AC 20. Some builds can reach AC 25+, but that's exceptional.
Spell Memorization → Spell preparation + spell slots
You prepare a LIST of spells each day. You can then cast ANY of those prepared spells using your spell slots. No need to memorize Fireball twice to cast it twice!
Material Components → Component pouch or focus (most ignored)
Unless a component has a gold cost listed, you can use a component pouch or arcane/divine focus. Most tables ignore components entirely unless they have a cost.
Alignment Restrictions → Mostly suggestions now
Paladins don't have to be Lawful Good. Alignment is more of a roleplay guideline than a mechanical restriction.
XP for Gold → XP from encounters/milestones only
No more GP = XP. You gain experience from overcoming challenges (combat or otherwise) or when the GM awards milestone levels.
New Concepts
These mechanics didn't exist in 2e. They're fundamental to 5e!
Proficiency Bonus
A universal bonus (+2 at level 1, up to +6 at level 17+) added to everything you're trained in: attack rolls with proficient weapons, saving throws you're proficient in, skill checks for proficient skills, and spell attack rolls.
Advantage / Disadvantage
Roll 2d20 and take the higher (advantage) or lower (disadvantage). Replaces most situational modifiers. If you have both, they cancel out completely.
Bounded Accuracy
Numbers stay relatively small. A +10 is exceptional. This means lower-level creatures remain threats and high-level characters aren't invincible.
Concentration
Many powerful spells require concentration. You can only concentrate on ONE spell at a time. Taking damage forces a CON save (DC 10 or half damage, whichever is higher) or you lose the spell.
Cantrips
At-will spells that never run out. Damage cantrips scale at levels 5, 11, and 17 (e.g., Fire Bolt goes 1d10 → 2d10 → 3d10 → 4d10).
Bonus Actions
A secondary action each turn. Some abilities, spells, and class features use your bonus action. You can't take one unless something grants it.
Reactions
You get ONE reaction per round (resets at your turn start). Used for opportunity attacks, the Shield spell, Counterspell, etc. Triggered by specific events.
Death Saves
At 0 HP, you're unconscious but not dead. Each turn, roll d20: 10+ = success, <10 = failure. Three successes = stable. Three failures = dead. A 20 = regain 1 HP. A 1 = two failures.
Short & Long Rests
Short Rest = 1 hour (regain Hit Dice, some class features). Long Rest = 8 hours (regain all HP, half your Hit Dice, most features).
Hit Dice
During a short rest, spend Hit Dice to heal. Roll your class's die (d6 to d12) + CON mod per die spent. You have Hit Dice equal to your level.
Inspiration
A DM reward for good roleplay. When you have it, you can spend it to gain advantage on one roll. You either have it or you don't (no stacking).
Combat Turn Structure
No more segments or weapon speed! Combat is streamlined and fast.
Your Turn
Not Your Turn
Standard Actions
Key Combat Changes from 2e
- No weapon speed or initiative modifiers by weapon type
- Everyone rolls initiative once at start (d20 + DEX mod)
- You can move → attack → move more (split movement)
- Opportunity attacks when enemies leave your reach
- No facing rules (optional flanking variant exists)
- Attacks of opportunity don't exist - they're "opportunity attacks" now
Spellcasting Explained
The spell slot system is probably the biggest mental shift from 2e.
How It Works
- Spell Slots: You have X slots of each level (e.g., 4 first-level, 3 second-level)
- Prepared Spells: Each day, choose spells from your list (usually = ability mod + level)
- Casting: Spend a slot of appropriate level to cast ANY prepared spell
- Upcasting: Many spells get stronger when cast with higher slots
Example
Rudiger (Wizard) has 3 first-level slots and prepares:
- Magic Missile
- Shield
- Sleep
Important Mechanics
🧘 Concentration
Only ONE concentration spell active at a time. Taking damage = CON save (DC 10 or half damage) or lose the spell.
📿 Ritual Casting
Spells marked (ritual) can be cast in 10 minutes without using a slot. Great for utility spells!
✨ Cantrips
At-will, unlimited use. Damage scales at levels 5, 11, 17. You always have something to cast!
🎯 Attack vs Save
Spells either require YOUR attack roll OR the target's saving throw - never both.
5e 2024 Specific Changes
These are new even compared to 5e 2014. Most online resources don't cover these yet!
Species (formerly "Race")
- Ability score bonuses now come from your background, not species
- Species provide unique traits, senses, and abilities
- Many species have been updated with new or revised features
- Terminology changed from "race" to "species" throughout
Backgrounds
- Now provide an Origin Feat at level 1 (e.g., Magic Initiate, Skilled)
- Determine your starting ability score bonuses (+2/+1 or +1/+1/+1)
- Include skill proficiencies and starting equipment
- More mechanically important than in 2014 5e
Weapon Mastery
- Martial classes get mastery properties on specific weapons
- 8 mastery properties: Cleave, Graze, Nick, Push, Sap, Slow, Topple, Vex
- Can change which weapons you have mastered when you level up
- Adds tactical depth to weapon choice
Class Updates
- Most classes have been revised with updated or new features
- Subclass levels have been standardized (most at level 3)
- Some new subclasses added to existing classes
- Spell lists reorganized (Arcane, Divine, Primal)
Rules Glossary
- Official, standardized definitions for game terms
- Conditions clearly defined with consistent effects
- Keywords like "Emanation," "Unarmed Strike," "Exhaustion" clarified
- Makes rules arguments easier to settle!