I think the problem is that a lot of people are stuck with the 3e Fighter damage concept of a miss = 0 damage dealt.
Since they are making more abilities (at will abilities, useable every round) more like the wizard of 3e, there's going to be plenty of abilities that do damage even when you miss. However, people with evasion (rogues and shield wielding fighters) will still be able to avoid that "on a miss" damage.
So Cleave really doesn't break anything in this case. A fighter can choose to have the options of doing at least some damage on a miss on his target, or risk missing and doing no damage on his target, but guaranteed damage on an adjacent target. Basically, you are just moving where that "auto damage" is going to.. the primary target but only if you miss, vs secondary target but only if you hit the first.
The only problem I can see with the wording is the potential for reach/invisibility abuse. However, since the wording also says "3 damage" instead of some scaling thing... it's likely the full wording in the books will be something more like the following:
Hit: [W] damage, and an adjacent opponent to the target within your reach and that you can perceive takes damage equal to your Str bonus. (Or maybe 1/2 level + Str bonus).
Honestly, I cannot see a problem with an ability like that. In a game where wizards can force damage even on a successful save... giving this to Fighters really doesn't break any new ground or anything.
Since they are making more abilities (at will abilities, useable every round) more like the wizard of 3e, there's going to be plenty of abilities that do damage even when you miss. However, people with evasion (rogues and shield wielding fighters) will still be able to avoid that "on a miss" damage.
So Cleave really doesn't break anything in this case. A fighter can choose to have the options of doing at least some damage on a miss on his target, or risk missing and doing no damage on his target, but guaranteed damage on an adjacent target. Basically, you are just moving where that "auto damage" is going to.. the primary target but only if you miss, vs secondary target but only if you hit the first.
The only problem I can see with the wording is the potential for reach/invisibility abuse. However, since the wording also says "3 damage" instead of some scaling thing... it's likely the full wording in the books will be something more like the following:
Hit: [W] damage, and an adjacent opponent to the target within your reach and that you can perceive takes damage equal to your Str bonus. (Or maybe 1/2 level + Str bonus).
Honestly, I cannot see a problem with an ability like that. In a game where wizards can force damage even on a successful save... giving this to Fighters really doesn't break any new ground or anything.