Your second sentence isn't actually right, you know... considering the DMG advice to say "yes" rather than say "no", the default mindset for 4e is supposed to be permission rather than denial.
Cheers
Plane Sailing, I was in a hurry and answered the question quickly, but I understand your comment on such a terse response invoking the "sacred mantle of RAW." Reducing the area of effect of a close power is a significant effect which the OP may or may not have realized. There will almost certainly be an ability/power/feat like this in a splat book. There is already a paragon ability that is similar which hints at the level of power the designers placed on this ability. This is the rules forum not the house rules one, and I don't think there is any controversy that ad hoc change to a spell area of effect on the fly is a house rule. I do think you have a valid point on the "Say yes" idea now being part of the RAW.
Like some others have commented I don’t believe this is a “Say yes” circumstance. You say “yes” to things that encourage interesting play, things that encourage characters (and players) to do awesome stuff or are just plain fun. Typically, IMHO, this means certain circumstances the characters can set up and it is something that is an exception to make a certain game scene special.
You do not “Say yes” for just changing the rules because one of your players thinks it’s a great idea. There needs to be a gain to the whole game and all the players. “Say yes” does not mean saying yes when a player begs you to let him have [2W] on a power that is just [W]. Sure I can see giving bonus damage as a result of doing something cool, but not all the time.
I believe you are being encouraged to “Say yes” to players when they try to do things *not* covered or only minimally covered by the rules. For when the characters and players are stretching their imaginations not digging through the rulebooks.
Walknot, I believe you should be very consistent in your general rule applications. I believe having a DM who is consistent in his rules allows the players to know what to expect and think more about what cool thing are we going to do *in* the game instead of what cool thing can we con/bribe/trick the DM into *this* game. IMO you get better immersion in your game. I don't see a problem with changing you mind on something that is not working or not fun, but I believe it better to avoid changing rules often.
I also believe that if you are not going to railroad you players down a plot path then you have to let the characters choices matter. Deciding to take a Close, Range, Area, or Burst spell is an important choice for a character. The mix of spell types is also important. So important in fact, they let the players change these choices now.
I’m not anti “Say yes,” I actually think it is a great way of thinking. I just believe the results from “Saying yes” should be for a limited area, time or circumstance. I don’t think it was meant to be a back door way of justifying changing the rules.
