For the statistic from Poxnora 1, see Attack (strength)
Attacks are the main way to cause damage, and only Passive champions do not have a basic attack. This means most champions can spend AP to attack at their range. The champion's minimum range and maximum range determine how close and far it can attack. Many abilities also trigger off of attacks.
Types of attacksAugment
Attacks usually state a type of attack damage, such as Attack: Physical or Attack - Fire. Note: some abilities state a manner of attack, such as Attack: Gun. The damage type of these attacks may be read in the ability's rule text.
Also note some attacks are basic attacks, and some are nonbasic attacks. Basic attacks specifically say "basic attack", and nonbasic attacks just say "attack". For example, Power Attack is a nonbasic attack because it doesn't mention "basic attack". See Basic Attack for more information.
The first attack costs 3 AP by default, and subsequent attacks cost more. The "attack chain" refers to the chain of AP costs for successive attacks in one turn. The second attack costs 2 AP more than the first attack; the third attack costs 3 AP more than the second attack, and so on. (Note that some abilties such as Power Attack cost additional AP beyond what the base attack chain costs.) So costs of attacks are as follows:
First attack: 3 AP (+ any additional AP cost of the ability)
Second attack: 5 AP (+ AP cost)
Third attack: 8 AP (+ AP cost)
Fourth attack: 12 AP (+ AP cost)
Theoretically, a champion can make as many attacks per turn as it has AP. Usually champions will only be able to make 1 or 2 attacks per turn, since they can't store enough AP to make more than 2 attacks.
Abilities on the attack chainAugment
Note that many "attack related" abilities are on the attack chain, even if they don't count as attacks. (See Cone abilities for more information.) For example, Pounce and Frost Cone do not count as attacks, but they do increase the cost of attacks later that turn as if you had make an attack. So they are said to be "on the attack chain".