The Barbarian's Rage ability gives advantage on Strength checks and saving throws.
Does this mean that the Barbarian gets advantage to attack rolls as well? Is an attack a check, or since saving throws are mentioned, that means it does not apply to attacks?
No, an attack is not a check.
The similarity between a check and an attack is in the way that rolls are handled, bonuses are added to the rolls and advantages/disadvantages are given. I believe the developers linked them together in order to not have to explain the same thing twice.
Throughout the document, the developers specifically mention checks AND attacks. When they talk about advantage/disadvantage, they point out that you can get this on a check, an attack roll or a saving throw.
Under each of the attributes, Checks, Attacks and Saving Throws are all outlined in their own manner. This trend continues through the playtest document. It would be redundant to do this if checks and attacks were the same.
The difference between ability checks, saving throws and attack rolls is clearly delineated in "Chapter 7: Using Ability Scores" of the Player's Basic Rules and Player's Handbook. Specifically,
The three main rolls of the game—the ability check, the saving throw, and the attack roll—rely on the six ability scores. The introduction describes the basic rule behind these rolls: roll a d20, add an ability modifier derived from one of the six ability scores, and compare the total to a target number.
This chapter [7] focuses on how to use ability checks and saving throws, covering the fundamental activities that creatures attempt in the game. Rules for attack rolls appear in chapter 9. (PBR, p. 57; PHB, p. 173)
Under the subsection Advantage and Disadvantage, it again indicates that these are separate rolls.
Sometimes a special ability or spell tells you that you have advantage or disadvantage on an ability check, a saving throw, or an attack roll. [Emphasis added] (Ibid.)
Attacks also are the only rolls that follow the natural 1 and natural 20 rules. All other rolls treat 1 and 20 just like any other number.
From the PHB, page 173:
The three main rolls of the game—the ability check, the saving throw, and the attack roll—rely on the six ability scores. The book’s introduction describes the basic rule behind these rolls: roll a d20, add an ability modifier derived from one of the six ability scores, and compare the total to a target number.
This chapter focuses on how to use ability checks and saving throws, covering the fundamental activities that creatures attempt in the game. Rules for attack rolls appear in chapter 9.
This makes it clear that there are 3 distinct types of rolls. They share the same basic principle of roll a d20 and add an ability modifier, but they have separate rules for each type of roll that appear in different places.
For example, compare ability checks, from page 174:
To make an ability check, roll a d20 and add the relevant ability modifier. As with other d20 rolls, apply bonuses and penalties, and compare the total to the DC. If the total equals or exceeds the DC, the ability check is a success—the creature overcomes the challenge at hand. Otherwise, it’s a failure, which means the character or monster makes no progress toward the objective or makes progress combined with a setback determined by the DM.
To attack rolls, from page 194:
When you make an attack, your attack roll determines whether the attack hits or misses. To make an attack roll, roll a d20 and add the appropriate modifiers. If the total of the roll plus modifiers equals or exceeds the target’s Armor Class (AC), the attack hits. The AC of a character is determined at character creation, whereas the AC of a monster is in its stat block.
[...]
Rolling 1 or 20
Sometimes fate blesses or curses a combatant, causing the novice to hit and the veteran to miss.
If the d20 roll for an attack is a 20, the attack hits regardless of any modifiers or the target’s AC. In addition, the attack is a critical hit, as explained later in this chapter.
If the d20 roll for an attack is a 1, the attack misses regardless of any modifiers or the target’s AC.
These are clearly different rulesets with some mechanics in common and some distinct. Note that the text for ability checks clearly calls out "other d20 rolls"; one more point of evidence that not all d20 rolls are ability checks.
No, an attack is not a check. It's saying "similar to" in that intro paragraph just for total noobs to stress that you add a d20 and add an ability modifier to it. Nowhere else when it talks about attack rolls (especially in the Combat section) does it indicate that they count as a check.
And damage is certainly not a check. You are wanting to read this as"+2 to Strength" but that's not what it's doing.
There are two references to attacks as checks in the DM Guidelines document. I can't quote them here at the moment due to NDA, but I can give approximate locations:
Reading both references seems to give me the vibe that they intended it to be the same 'core mechanic', but with attack as a specialized (and common) form of it.
Whether the intention of the strength bonus in Rage was only for 'regular' checks, I am unsure of this. However, as a DM I would take the liberty to apply the +2 to hit (not damage) since strength does take a factor in how well you can hit with melee weapons.
Technically, an attack roll is a "check", but it's not a strength check. It's a skill check of your proficiency with a given weapon against an opponent's AC.
Just because a check might have a strength modifier associated with it does not make it a strength check. Just as a perception check is not a wisdom check. They aren't the same things...Wisdom may make you more perceptive, but perception check is not a wisdom check.
Quote from PHB.
"ABILITY CHECKS An ahility check tests a character's or monster's innate talent and training in an effort to overcome a challenge. The DM calls for an ability check when a character or monster attempts an action (other than an attack) "
