Here is an introduction to Marvel vs Capcom.  It will go through many things that beginners to this game should know about.  Even though Marvel vs Capcom is similar to the vs games which preceded it, MvC introduces some new moves and situations for which new strategies and tactics have been developed.  You'll see what I mean in a second.

I use a certain system when I list the moves of the characters.   This system will be used throughout the site, and I believe it is the easiest one to understand.  It is very straightforward and clear.

The six buttons:         ( )             ( )            ( )
                                Jab         Strong      Fierce

                                 ( )             ( )            ( )
                               Short      Forward  RoundHouse  

This has been the notation on the buttons since day one, so I assume most of you  have memorized it by now.  There seems to be some confusion with the Forward button.  When I say Forward, some of you think of this: .  I will clear up this confusion by displaying the image when I mean walk forward, and I will put Forward Kick when I mean the kick.

Explanation of combo systems

The Magic Series
The Magic Series is one of the most appealing aspects of the vs series.  This is the ability of each fighter to link their attack buttons together while attacking. To do the series though, you have to connect with the first hit.  It doesn't matter if the opponent is blocking or not. Each fighter has a ground, jumping, and super jumping magic series.  You can only go forward in a series, not back.  I will give examples of this in the preceding definitions. 

Hunter Series - The most desirable series.  Your character can link all of the attack buttons into his/her combo.  For example, Strider Hiryu has the Hunter Series.  So, he can combo you with Jab, Short, Strong, Forward, Fierce, RoundHouse.  Or he could skip around and combo you with Short, Strong, Fierce, RoundHouse.  However, he could not combo you with Strong, Short, Fierce.   You can only go forward in a magic series, never back. 

Weakest to Strongest - This is a good series, but not as good as the hunter.  Basically, you can link a weak (Jab Punch or Short Kick) to a stronger (Strong Punch or Forward Kick) attack or to the strongest (Fierce Punch or RoundHouse Kick) attack. Remember, you can also just do Jab Punch to RoundHouse Kick or Forward Kick to a  Fierce Punch. You don't have to do all the buttons.

Weakest to Any - The character is able to chain a weak (Jab Punch or Short Kick) to one button of stronger strength.

Punch to Kick - Just like the name says, you can link a punch to a kick or greater or equal strength (Remember, you can't go back in a magic series).

None - Has no magic series.

Explanation of new and common elements in the vs series

Helper Characters (new)
You now have helper characters.  Like in MSHvsSF you could make your second character come in and attack.  However, he could be hurt.  Now you have a third character whose only purpose is to come in and make those  attacks.  Each Helper can be used a certain amount of times.  So far, there are 22 known helper characters.

Early Hyper Level (new)
When you begin battle, you already have one level of super bar stored.  You have to be more careful now, as some "skilled" player can nail you with a super right from the start and get you off on the wrong foot.

The Two on One (new)
This is the most noticeable addition to the vs series.  Your teammate jumps in and both of you are on the screen for about 10 seconds.  You control both of your characters, which is kind of awkward since you have one controller.  In addition, you'll have a maxed out hyper gauge, so you can super as much as you want.  It uses up 2 levels of super, but if you use it with 3, it will last 15 seconds as opposed to 10.  Right now, the only use I have found for this move is block damage.  Only initiate this move if your opponent is close to you, because then your teammate will jump on the other side of them.  If the opponent is far away from you, both members of your team will be on the same side and your opponent will be able to block everything.

Regaining Life
During battle, you may get damaged and lose life.  You'll notice that of the damage inflicted, some of it completely reduces the life bar, and the rest of it is represented by a red bar.  If you switch characters, so that the person who was injured was inactive, their life bar will begin to refill and they'll slowly regain life, up to the amount shown in the red bar.   Wolverine has a 'healing' power that is always active and so regains more life while inactive than other characters.

Easy Mode
This is for people not very combo-oriented or have just begun playing the game.  If you press certain buttons together, you will be able to perform special moves and combos.  I personally believe this feature sucks, and should not be used even for beginners.  Go out there, get the moves, and start playing normally.  You must always be in control, which is the opposite of easy mode.  

General Moves

Guard   Hold / on the ground or in the air.
Reduces/nullifies damage from attacks.   However, you can be thrown even though you are blocking.

Dash   Tap , or press 3 punches.
Your character will dash/roll/hop forward.  This gives you momentum, allowing you to get more hits in a ground combo.  Excellent way to initiate a combo.

Backstep   Tap , or press + 3 punches.
Your character will dash/roll/hop backward.

Super Jump  Tap , or press 3 kicks.
Your character leaps high up.  After a launcher, just press up to execute it.

Advancing Guard   Press 3 punches while blocking.
Your character "shoves" forward while Tap 3P while blocking blocking. This can be used to reduce block damage and to move closer to your opponent, but it's possible to get knocked out of an Advancing Guard.  Use it against people who like to get in close and start comboing you. 

Tech Hit   Press + Punch when thrown.
Your character will immediately escape any normal throw and take minor or no damage.   Use it when you are playing against cheesy throwers.

Roll   + Punch when falling or when sweeped.
Upon landing, your character will roll forward, effectively avoiding any OTG your opponent had been thinking of.

Taunt   Press START.
Your character taunts the other player.  Effective for getting your opponent mad.

Switch Fighter   Fierce Punch + RoundHouse Kick (you have to have both fighters alive)
You will taunt, then leap away as your teammate comes in with an attack, and taunts before becoming controllable. 

Call Helper Character   Strong Punch + Forward Kick
One of your helper characters will appear and perform an attack. Costs one helper stock.

Variable Counter   + Punch (while blocking)
Your teammate will jump in and counter with an attack.  In general, it is a safe way to switch characters.  However, it is possible to do this and have both characters eat an attack.  Costs one Hyper Gauge stock.

Team Super   + Fierce Punch + RoundHouse Kick
Your character will begin a predetermined Hyper Combo. A moment later, your other teammate jumps in and performs their predetermined Hyper Combo, and you are left controlling the teammate who just jumped in. Costs two Hyper Gauge stocks.

Two on One   + Fierce Punch + RoundHouse Kick
Your teammate will jump in and both of you will taunt. Afterwards, you can control both characters with the controller for a limited period of time. In addition, you'll have a maxed out Hyper Gauge.  (explained in further detail above)

Helper Characters

Here is a detailed explanation of what each helper character does when you call them for assistance.

To see the codes on how to select your helper, please go here.

Unknown Soldier - Forgotten World
He shoots out some beams at your opponent covering most of the bottom half of the screen.

Tia - Capcom Mascot
She makes a whole bunch of dice rain down where your character is standing.

Anita - Darkstalkers
Her disembodied doll heads float around her as she walks forward, making a shield of sorts. Eventually, she will release her doll heads forward.

Lou - Chariot
He's an elf that shoots several arrows at your opponent.

Michelle Heart - Wings of Ales
She appears on the same level as the opponent and shoots beams in three directions.

King Arthur - Ghosts and Goblins
He throws lances at your opponent. The fun part is that if he gets hit, he loses his armor just like in his own game!

Saki - Nigiirochou no Kiseki
She shoots a laser at your opponents.

Ton-Pooh - Strider
He does a long range kick in the middle of the screen.

Devilot - Cyberbots
She comes in on a mech which self-destructs after a LONG time. It's unblockable though.

Psylocke - X-Men
She does a Psi-Thrust super on your opponent.

Iceman - X-Men
Makes a whole bunch of ice blocks fall onto the screen

Cyclops - X-Men
Optic blasts his opponent. Uses his low(jab) optic blast.

Thor - Marvel Comics
Shoots thunder at his opponents.

Storm - X-Men
She throws out a vertical typhoon in the middle of the screen.

Jubilee - X-Men
Shoots out several firecrackers at different angles that slightly track the opponent, pops her gum and leaves!

Juggernaut - X-Men
Comes barreling toward the opponent, doing a weak version of his Juggernaut Headcrush. Fills the entire screen.

Rogue - X-Men
She does her rushing punch special from XSF. Starts from the middle of the screen and moves diagonally upward.

Colossus - X-Men
Shoulder charges the opponent.

Magneto - X-Men
Throws out an EM disrupter.

US Agent - MSH vs SF
Does a Charging Star across the screen.

Secret Helpers:
Shadow - MSH vs SF
Does his Somersault Super move(the one where he does three flash kicks).  Good anti-air.

Sentinel - XCOTA
Flies across the screen and physically attacks the opponent. Mostly fills the entire screen.