Intro
As an old 1st. edition DM, combat in 5E always feels unusually easy for the players. Yes, the monsters have more hit points, sometimes a LOT more, and spells do more damage, but it seemed more than that. While preparing to run an old school game for my 5E players, I realized something else: The armor class system is skewed as well.
Bonuses and Armor Class
The first thing to understand about older editions of D&D is that each class grouping (Fighters, Clerics, Thieves, and Magic-Users) each had a different to hit chart. Fighters were the best and improved the fastest, Magic-Users (ie, mages or wizards) had the worst and improved the slowest. Also, stat bonuses were lower. A 17 strength in 1st is +1 to hit and damage but 17 in 5E is +3. They did limit magic item bonuses to +3 in 5E instead of +5, but that only affects weapon using classes. Since 5E seems to be written primarily by what I call "Whiny Wizard players", that's not significant to me. Since every class in 5E starts with the same Proficiency bonus (+2), that means the hit roll for AC10 at 1st level is only 8, instead of 10 in 1st. So, let's look at some numbers.
| Level | Fighter | Cleric | Thief | Magic-User | Monster | 5E (ALL classes) |
| 1 | 0 | 0 | -1 | -1 | +1 | +2 |
| 5 | +4 | +2 | +1 | -1 | +5 | +3 |
| 9 | +8 | +4 | +4 | +1 | +8 | +4 |
| 13 | +12 | +8 | +6 | +4 | +11 | +5 |
At low levels, 5E characters are significantly better to hit, at mid-levels it evens out, and then 1st jumps ahead (and Fighters are WAY better) at higher levels. But remember, stat bonuses are higher in 5E.
EDIT- I went back and added 1st. edition monsters. It looks pretty good, but bear in mind, monsters in 1st don't have attribute stats (ie, no Strength, Dexterity, etc) so they don't have any additional bonuses.
| Strength to hit | 15 | 16 | 17 | 18 |
| 1st | 0 | 0 | +1 | +1 |
| 5E | +2 | +3 | +3 | +4 |
| Dexterity to hit | 15 | 16 | 17 | 18 |
| 1st | 0 | +1 | +2 | +3 |
| 5E | +2 | +3 | +3 | +4 |
Also, the highest bonus for a player character in 1st is +3, but 5E stats go to 20 and are +5.
Armor Class
And here's the last thing I noticed this weekend: armor classes are generally lower in 5E. Here are some typical monsters with their AC adjusted to 5E.
| Monster | 1st | 5E |
| Orc | 14 | 13 |
| Ghast | 16 | 13 |
| Mimic | 13 | 12 |
| Werebear | 18 | 11 |
| Troll | 16 | 15 |
| Hill Giant | 16 | 13 |
| Vampire | 19 | 16 |
| Air Elemental | 18 | 15 |
| Lich | 20 | 17 |
| Pit Fiend | 23 | 19 |
| Glabrezu | 24 | 17 |
| Succubus | 20 | 15 |
A 1st level fighter with 18 strength rolling to hit an orc needs to roll a 13 on the die in 1st, but a 5E fighter only needs a 7! The lower AC in 5E compensates for the higher fighter bonus in 1st at higher levels, EXCEPT ALL CLASSES in 5E have the same proficiency bonus. So non-fighters have a MUCH easier time hitting targets in 5E than their 1st edition counterparts. A 9th level 1st ed. wizard with 18 Dex needed a 16 on the die to hit a succubus. A 5E wizard needs only a 7!!
Attacks per Round
Multiple attacks per round come faster in 5E as well. 1st fighters get 3/2 at 7th and 2/1 at 13th. 5E fighters go straight to 2/1 at 5th, 3/1 at 11th and 4/1 at 20th. The worst thing is combat cantrips in 5E. Combat cantrips allow spellcasters to deal out multiple damage or attacks equal to fighters without using spell slots. They get quad damage at 17th whereas fighters have to wait until 20th.
| 1st | 5E | ||
| Level | Fighter | Fighter | Cantrips |
| 1 | 1 | 1 | x1 |
| 5 | 1 | 2/1 | x2 |
| 11 | 3/2 | 3/1 | x3 |
| 20 | 2/1 | 4/1 | x4 |
Surprise, Initiative, and Spell Casting
In 1st, one combat round is one minute, broken into 10 six second segments. Spells have casting times, which are generally in one segment per spell level (Magic Missile is one segment, Fireball is three, Cone of Cold is five). Some spells have a full round casting time. In 5E, a round is just six seconds, equal to an old segment, and most spells take a single action, meaning their casting times are six seconds or less. Spell durations are altered in 5E, sometimes one old round being one new round to preserve relative combat times. But many spells suffer, Fly in particular. Fly was 20 minutes per caster level plus 1d6 x ten minutes. A 5th level mage could fly for 110-160 minutes, but a 5E caster is limited to a maximum of ten minutes. And its concentration, meaning taking damage can end it early (you better have Feather Fall memorized!).
Surprise is rolled whenever there is a chance that one or both side is unaware of the other, either through a deliberate ambush or opening a door unaware that the other side is beyond it. Surprise is a simple d6 roll with a roll of 1-2 equaling being surprised. It is possible for both sides to be surprised or neither. If one side is surprised, then you subtract the lower side's roll from the higher, which gives the number of surprise rounds, each of which is basically equal to a round of combat. So Party A rolls a one and is surprised and Part B gets a four and is not surprised and now gets to take three rounds of free attacks on Party A. Surprise is brutal in 1st. If one side rolled a six and the other a one, five rounds of surprise could end the battle without the losing side ever getting an attack. If Party A rolls a 2 and Party B rolls a one, both sides are surprised for one round, then Party A gets one surprise round, since they recovered faster.
However, that's melee. Spellcasting in surprise uses the spell's casting time. In the four versus one surprise roll, the winners have three surprise rounds, each of which is equal to a segment in "real time". A wizard on the surprise team could cast Magic Missile three times or Fireball once.
Initiative is also by group, using a d6 and rerolling every round. Dexterity is not a factor in regular initiative. Before rolling, each player states their planned action, then initiative is rolled. This makes spellcasting in melee difficult. The DMG actually discourages freely casting spells in combat, saying wizards should rely on items like wands for casting in combat. But back to the example. The wizard player declares they are going to cast Fireball and the party rolls initiative. The DM wins and the NPCs go first. The DMG emphasizes intelligent monsters will target spellcasters who are casting. Also, while spellcasting, the caster can't move and they lose their dexterity bonus to armor class. Any successful hit automatically breaks their casting and the spell is lost. Formation fighting is much more important in 1st. Also, most battles were dungeon fights in close quarters. Also, all healing spells are by touch, meaning the party needs to stay tightly grouped with their cleric able to reach everyone. But, in small parties, clerics were often on the frontline as the second-best melee fighters.
In this case, the orcs on the front line can't reach the sorcerer in back, but the orc archers could try to shoot past their teammates, accepting the risk of friendly fire.
Since casting in 5E is effectively instantaneous, there is no way to break a spellcaster's casting (if there was a tie, that could work). Thus, the creation of Counterspell. However, per my discussion in Wizard Duels, caster on caster spell combat at low levels is effectively the same as melee. But once they have Counterspell, it becomes a race to deplete the other side of high level slots ("Fireball!" "Counterspell!" "My turn, Lightning Bolt!" "Counterspell!", etc) unless, again as in 1st, they have wands since spells cast by items can't be blocked with Counterspell.
D10 Initiative and Casting Times
In 1987 (I think…) I went to RIT in Rochester for their Rudicon gaming convention. A couple of friends went to school there, and the roommate of one introduced me to the d10 initiative system. Simply put, your roll on the die is what number segment you take your action in, low rolls go first. Your Dexterity modifier is subtracted from your roll, so higher Dexterity characters will tend to go first, but not always. Now here's the big thing: spell casters add the spell's casting time in segments as a penalty. You roll a five, subtract two for your 17 Dexterity, giving you a three. But you are casting Fireball with a casting time of three segments, so now your final initiative is six. BUT! You start casting on three and finish on six, so if you are hit on segment four or five while you are casting, your spell can be interrupted. Long spells may take you into the next round. If your final roll is eight, and you want to cast Fireball, you will go off on one in the next round! (8+3=11, so 1 in the next round)
Implementing Casting Times in 5E
I have considered bringing casting times into 5E. I even bought the Survivalist's Guide to Spelunking book partly because they said they had a casting time system for 5E. One of the authors worked on 1st edition, so I was interested to see their ideas. Unfortunately, you can't assign casting times individually to spells in 5E, that would just be too much work, so they came up with a simplified system. The spell's level or the slot being used, whichever is higher, is the "casting time" and is applied as a penalty to your initiative. Casting a 3rd level spell or using a 3rd level slot subtracts three from your initiative. As in the d10 system, your base initiative is when you start casting and your modified roll is when you finish and release the spell, meaning you can be hit and interrupted while casting. Cantrips and spells that are cast with a Bonus action, Reaction, or are longer than an action are unchanged. They do add some alternate rules to speed up spellcasting initiative, including one for Warlocks, since they have so few spell slots getting interrupted is more serious for them.
Addendum- Back in the day, some DMs would let you use Dispel Magic the way we use Counterspell in 5E. You had to cast Dispel Magic while the enemy mage was casting, but since there was no to hit roll or saving throw, it could be more effective. Especially if you were out of offensive spells. The plot justification was Dispel Magic disrupted the gathering of magic needed to cast a spell.
