Your Strength (Athletics) check covers difficult situations you encounter while climbing, jumping, or swimming. Examples include the following activities:
Jumping: You can use the Athletics skill to make jumps. You can make a long jump with a number of feet equal to your skill check. You can make a high jump equal to your skill check result divided by four. Creatures with greater than 30’ movement gain advantage on any running jump check
Pole Use: If you use a pole as part of an Athletics jump check you gain advantage on the check (but must drop the pole).
Faster Base Movement: Creatures with a base land speed above 30 feet have advantage on Acrobatics checks. Creatures with a base land speed below 30 feet suffer disadvantage on Acrobatics checks made to jump. No jump can allow you to exceed your maximum movement for the round.
Climbing: With a successful Athletics check, you can advance up, down, or across a slope, wall, or other steep incline (or even across a ceiling, provided it has handholds) at half your normal speed. A slope is considered to be any incline at an angle measuring less than 60 degrees; a wall is any incline at an angle measuring 60 degrees or more. A climb check that fails 5 or less means that you make no progress, and one that fails by more than 5 means that you fall from whatever height you have already attained. The DC of the check depends on the conditions of the climb. Compare the task with those on the following table to determine an appropriate DC.
You need both hands free to climb, but you may cling to a wall with one hand while you cast a spell or take some other action that requires only one hand. While climbing, you can’t move to avoid a blow, so opponents have advantage on their attacks against you. You also do not gain the benefits of a shield while climbing. Anytime you take damage while climbing, make an Athletics check against the DC of the slope or wall. Failure means you fall from your current height and sustain the appropriate falling damage.
If you can brace yourself against another wall or surface, you gain advantage on the check. If any of the surfaces are slippery (from rain, greased, etc.) the checks are made with disadvantage. You can also climb at full speed by making the Athletics check with disadvantage. The use of pitons (or a climber’s kit) grants advantage.
Catch Yourself When Falling: It’s incredibly difficult to catch yourself while falling. Make an Athletics check with a DC equal to the climb DC at disadvantage to do so.
Catch a Falling Character While Climbing: If someone climbing above you or adjacent to you falls, you can attempt to catch the falling character if he or she is within your reach. Doing so requires a successful Athletics check DC 20 (possibly more or less by circumstance). If successful, you must immediately attempt a climb check equal to the climb DC. Success indicates that you catch the falling character, but his total weight, including equipment, cannot exceed your heavy load limit or you also fall.
Expeditious Climb: In return for suffering disadvantage on your Athletics check to climb, you can move with such speed and vigor that you do not lose your Dexterity bonus to AC while climbing and climb at your full movement speed.
Slow Descent: It is possible to slow your descent if you fall. You might attempt to grab ahold of rocks, branches or vines when falling. If you make a DC 15 Athletics check, you are able to reduce your effective falling height by 10’. At DC 25 you can reduce your falling height by 20’.
Swim: Make a Strength (Athletics) check once per round while you are in the water. Success means you may swim at up to half your base speed as your movement. If you fail by 4 or less, you make no progress. If you fail by 5 or more, you go underwater.
If you are underwater, either because you failed an Athletics check or because you are swimming underwater intentionally, you must hold your breath. You can hold your breath for a number of rounds equal to twice your Constitution score, but only if you do nothing other than movement or free interactions. If you take an Attack action or other strenuous action, the remainder of the duration for which you can hold your breath is reduced by 1 round. (Effectively, a character in combat can hold his breath only half as long as normal.) After that period of time, you must make a DC 10 Constitution save every round to continue holding your breath. Each round, the DC for that save increases by 1. If you fail the Constitution save, you begin to drown. The DC for the swim check depends on the water, as given on the table below.
Each hour that you swim, you must make a DC 20 Constitution save or gain a level of exhaustion.
Swing on Vines: The deep forests and jungles of the world are choked with hanging vines and flexible branches. Some characters can use these objects as impromptu ropes and swing lines, giving them the ability to move with incredible speed, far removed from the dangers of the forest floor.
In order to use Athletics in this manner, there must be sufficient flexible branches and vines for you to grasp and they must be long enough to allow you to swing between trees. For this reason, this skill use can only be used in forest, jungle, and some swamp terrain (specifically, swampy forests). The DC of moving along using this skill use is a base of 20. Failure by 4 or less means you do not move but can try again (having missed your next hand hold failure by 5 or more results in you falling (and possibly taking falling damage).