[draft]

Free climbing

• Each successful Strength (athletics) or Strength (acrobatics) check moves the climber up to their climb speed
• A failed check means the climber does not advance, but there are no other immediate effects
• After making climb attempt, successful or not, equal to 3+their Constitution modifier, the climber must make a DC10 Constitution save after each further attempt (successful or not) or gain one level of exhaustion and fall from their current position.

Assisted climbing

• Hardware has a base failure chance, modified by the skill of the person who placed it. The placement check is not made until the point of crisis.

further considerations

• rest points: ledges or other opportunities to pause and reset attempts
• complications: chance each attempt of wind, falling rocks, birds or other interference that might cost an attempt or cause an actual fall or other ill effect