Ability Checks

Definitely an ability check when she lands.

Ability checks are a fundamental game mechanic used to determine the success or failure of a character's action, typically as a response to a situation outside the character's control. Each situation is assessed regarding which of the character's ability stats is the best reflection of the character's success: charisma in the case of the character being liked or respected; dexterity in where the character might stumble or fall; intelligence with regards to problem solving; wisdom with respect to knowing something; constitution where health is concerned; and strength if the character is attempting a physical feat of some kind.

Players cannot use an ability check as a course of action. Instead, they must state what they wish to do, and if an ability check seems appropriate, the dungeon master decides to impose one. More often in such cases, the character's sage abilities determine whether the character can perform that task or not; otherwise, the DM may simply say "yes" or "no" without the need of a check.

Method

To assess the character's success, the player is told to roll a d20 against the player's ability stat. Success is achieved when rolling equal to or less than the relevant ability.

Checks are always made against the character's current stat. Thus, if for whatever reason, the character's relevant ability has been lowered through damage or some form of attack, the adjusted stat is used when making the check.

Players need not make an ability check when success is guaranteed due to the character's ability. For instance, a character with a dexterity of more than 15 is assumed to catch an item thrown from ten feet away without the need for a check; in any case, such frivolous checks are rarely needed in real game play.

Complex Checks

In various cases, particularly when attempting to learn a skill, characters may need to make multiple checks against more than one ability stat; failure in any roll might be sufficient to nix success. On the other hand, it may be that success at any of the rolls being made is sufficient. It depends on the situation.

Occasionally, when one character fails an ability check, a nearby character may be given the opportunity to "save" the character.

For example, Margaret loses her balance when aboard a launch on high seas; she fails her dexterity, indicating that she's going to fall over the side. However — as John is within reach of Margaret, he's given a chance to roll against his own dexterity, to see if he catches her and stops her from falling overboard.

In another example, a character trying to leap ten feet onto a distant roof with limited running space would first make a strength check to clear the distance; then, a dexterity check would determine if a foothold on the sloped roof was gained.

In such situations, the DM should clarify before the jump which checks would have to be made, and in what order. Transparency is vital, and the DM (or the player) should not be forced to make checks that weren't disclosed ahead of time.

See also,
Player Characters
Stun Lock