I haven't seen the playtest rules, this is just a guess from designer comments etc.
They talk about making the same monster viable over a longer level span. They also talk about reducing the necessity of magic items. And they talk about Fighters who increase in options, not numbers.
What is this about? There are two major numbers that increase by level:
1. attack vs. defense (AC, Fort, Ref, Will) (spells used to have the target roll dice against spells previously, but which side rolls is unimportant mathematically)
2. damage vs. hit points (average damage per round over the encounter)
In a d20 system, each point of attack bonus equals a 5% change in to-hit chance.
If the attack bonus gets too low, the game is frustrating for players, because the PC just keeps missing. If the attack bonus is too high, it removes some excitement from the game, because combats boil down to slicing a monsters hp away until they are zero. There is no need for flanking, buffing, searching for weak spots or other tactics.
In other words, it's pretty important to keep the hit/miss ratio within a range where the game is fun.
Damage scaling is less sensitive, because the worst thing that can happen is that combats are too swingy or take too long. (And preferences vary from player to player here)
4E fixed the monster hit and AC progression at 1/level (and hp increase at 8/level). Previous editions were less explicit, but had similar ranges. PCs basic attack increased at 1/2 levels, and the remainder was filled with ability score increases, magic items, feats, and leader buffs.
If 5E halves monster progression to 1/2 levels, it removes a lot of pressure from PCs to keep up. If PCs progress at 1/3 or 1/4, there is a smaller gap to fill and feats, ability score increases, and items become less important.
It would also make monsters viable longer. A first-level orc with a 60% to hit a first-level character would still have a 40% chance to hit a 9th-level one. A noticable difference, but he'd still be viable as enemy.
They talk about making the same monster viable over a longer level span. They also talk about reducing the necessity of magic items. And they talk about Fighters who increase in options, not numbers.
What is this about? There are two major numbers that increase by level:
1. attack vs. defense (AC, Fort, Ref, Will) (spells used to have the target roll dice against spells previously, but which side rolls is unimportant mathematically)
2. damage vs. hit points (average damage per round over the encounter)
In a d20 system, each point of attack bonus equals a 5% change in to-hit chance.
If the attack bonus gets too low, the game is frustrating for players, because the PC just keeps missing. If the attack bonus is too high, it removes some excitement from the game, because combats boil down to slicing a monsters hp away until they are zero. There is no need for flanking, buffing, searching for weak spots or other tactics.
In other words, it's pretty important to keep the hit/miss ratio within a range where the game is fun.
Damage scaling is less sensitive, because the worst thing that can happen is that combats are too swingy or take too long. (And preferences vary from player to player here)
4E fixed the monster hit and AC progression at 1/level (and hp increase at 8/level). Previous editions were less explicit, but had similar ranges. PCs basic attack increased at 1/2 levels, and the remainder was filled with ability score increases, magic items, feats, and leader buffs.
If 5E halves monster progression to 1/2 levels, it removes a lot of pressure from PCs to keep up. If PCs progress at 1/3 or 1/4, there is a smaller gap to fill and feats, ability score increases, and items become less important.
It would also make monsters viable longer. A first-level orc with a 60% to hit a first-level character would still have a 40% chance to hit a 9th-level one. A noticable difference, but he'd still be viable as enemy.
