Wow, that really clears things up for me. I am a Marth player so I figured that it was essential to know how to do this. I use other characters but in general I need a lot of help. I suppose I should repeat what spacing is to make sure I get it, and I'll also try to explain what to do in a situation where they are closer than you want for your spacing.
Spacing is moving your character into a spot where your attacks can hit, but your body is further back and thus it keeps you safe. Attacking while being to close is risky because with proper spacing their shield has more lag. All attacks can be spaced, even aerials. Projectiles.... (Do projectiles have spacing?)
If someone has well placed spacing on you it would be intelligent to move so your shield has less lag time.
In a situation where your character is to close with most moves, it is intelligent to move back because you have many options while possibly avoiding your opponents attack.
So my next question would be: Do projectiles have spacing, and if so do the shields lag longer if the move doesn't go out as far.
I suppose that I should learn all my attacks reach to make sure I can use it in battle. I have a basic idea but missing never seems to be very good.
I tend to fight people who roll a lot. I am thinking that rolling's main use is to get behind a opponent who is in the midst of a smash or tilt or like Kirby's jab combo. My friends roll more often. I tend to use smash moves and short hop aerials in close combat unless I am walking where I am wide open to anything. In a situation where I am using smash moves and they are rolling around, should I get away to create situations where I can space properly, or should I predict where my opponent will be and try to smash or tilt or hit him?
When you hit the opponent's shield from a farther distance, they still undergo the same amount of lag than if it were a close distance. What matters is that you're farther away. Shield grabbing(Holding Shield, then pressing the attack button) is very potent in Brawl. You can shield grab non-disjointed hitboxes quite well. By being farther away, they already lack the option to shield grab.
Back the lag issue. As I said before, the hit lag is the same regardless of range. However, suppose you are far enough away to not be grabbed, but still close enough to be hit by their Ftilt, which comes out on frame 5. Let's also assume that they recover from the lag 15 frames(1/4 of a second)* before you do. Since they shielded your attack, they have to drop shield before they can use their Ftilt. On average, it takes 7 frames** from when your drop your shield to when you can first do an action. So in reality, they only have 8 frames to punish you. They can still Ftilt you, however.
But, if you use your attack from the farthest range possible-which is out of the range of their Ftilt-they still have only 8 frames to punish you. But you happen to be farther away, and their Ftilt can't reach you. They might be able to land a dash attack, but they have to start dashing first, and 8 frames is not that long, to be honest. For a comparison, Marth's Fair comes out on Frame 4.
To answer your question about projectiles, yes. They do have spacing. Let's use Lucas as an example. Lucas' Side+B(as I assume you know) has okay range. It can't go across the whole stage, but it's good enough. However, if he uses the projectile when he's too close to you-which is a spacing error-you can punish him-assuming that you managed to avoid it with your shield/spotdodge/etc. I hope this helps.
Your next question regarding what to do against people who roll: First off, aerials aren't your best option when you're right smack dab in front of your opponent. Using aerials when you're at the maximum range of Marth's sword is a better idea-avoid using Marth's Dair, it has a lot lag after it.
Using smash attacks at close range-especially with Marth-is not a good idea. He has enough lag on every single smash attack that the opponent can just stand right in front of you doing nothing, and manage to shield it every single time. Try using your Forward+B(It has multiple hits as you probably know, so learn the rhythm of it.) Having 4 hits in a row can really batter on an opponent's shield, and lots of newer players won't shield the whole thing. If it looks like an opponent will shield all 4 parts of the attack-which allows them to punish you about 50% of the time-then simply do not complete the move. Marth will move backwards a bit, and you can get out range from there.
Wow, I haven't even answered your rolling quesiton yet. Simply put, if you know your opponent is going to roll, make sure you're right there so you can punish them. If they love rolling behind you, start charging a smash in the oppisite direction as soon as they're front of your face. Only do this if you know that they'll choose to roll, instead of just shield it and punish like they -should- be. Or you can choose to do nothing when they're right in front of your face and see what happens-bad players are notorious for panicking when they're in close range.
The spacing option is also a viable one, but if you have a chance to punish their mistake, do it.
*Many attacks in Brawl are not safe on block-Marth is fortunate his Fair has little lag, good range, and his aerial mobility is enough for him to advance and retreat in the same shorthop.
**If you powershield an attack, you do not have the 7 frames of lag when dropping your shield. You can act immediatly after you powershield.
