How to use modifiers and checks

Question

We have just started playing 4e D&D (bought the books and then 5e comes out sigh) and I want to know what is the difference between the modifier and a check? For example, a character might have an Intelligence of 14 with a modifier of +2 and a check of +2. Some skills have modifiers but no checks or checks but no modifiers. When do you use a modifier and when do you use a check?

Answer 1

A modifier is the +2, that is, you gain +2 to all intelligence rolls.

A check is the roll itself. If you are trying to best someone at a game of chess, the DM might say "Make an Intelligence check". You would then roll a d20, add the intelligence modifier, and that would be your result.

However, more often than not you will have a skill associated with what you want to do. For example, if you want to study a plant and determine its origins, instead of making an Intelligence check, you would make a Nature check, using the nature skill. In general, Nature is reflective of your intelligence, but if you have trained in it due to your class (for example a Druid), you would use your Nature skill for the check.

In short, likely the way you are reading them can be used interchangeably. +2 on Intelligence checks is the same as a modifier of +2.

Answer 2

A Modifier is the bonus that you get based on an ability score. The Modifier is calculated as being (score-10/2) rounded down. Modifiers are used in Checks, and also in Powers and other locations.

A Check is what you get from adding a d20' result to any bonuses that that roll might have. However on a character sheet you will see some stats referred to as Checks or Skill Checks. These are the bonuses that you add to the d20 result. They are usually calculated as being (level/5) + (modifier) + bonuses. The Basic Checks (Strength, or Intelligence, etc.) usually don't have any bonuses, but the Skill Checks can get them from all sorts of places, including Training.

From your question is seems to me like you are wondering what is the difference between the +2 which is your modifier and the +2 which is your check. The check in this case refers to the bonus that you add to your roll, and the only reason your modifier is the same as your check is because you are making a level 1 character (at least that what I am assuming).