# Rule 20 (A.A.U. Four-Wall Rules, 1 January 1920, historical)

> **Historical rulebook: not the current rules.** The current rules are here: https://handball.theperfectship.com/rules/four-wall/

Every player is entitled to a free and unobstructed opportunity to play the ball. If he is interfered with unintentionally it is called a hinder and is played over. If a player is prevented by an adversary from seeing the ball until too late to get in position, it is called a covered ball and shall be played over.

## Mentioned here

- [Player](https://handball.theperfectship.com/player.md)
- [Hinder](https://handball.theperfectship.com/hinder.md)
- [Ball](https://handball.theperfectship.com/ball.md)

How this rule changed: [wording in every rulebook](https://handball.theperfectship.com/rulebooks/clause-history/code-fourwall-american/19.md)

## Relationships

- Player relates to Hinder: mentioned together in 7 sub-rules.
- Player relates to Ball: mentioned together in 13 sub-rules.
- Hinder relates to Ball: mentioned together in 7 sub-rules.

Rulebook: [A.A.U. Four-Wall Rules, 1 January 1920](https://handball.theperfectship.com/rulebooks/aau-fourwall-1920.md)

Source: Official Athletic Rules and Official Handbook of the Amateur Athletic Union of the United States (Spalding's Athletic Library, Group VII, No. 12A; American Sports Publishing Co., ©1920), rules in force January 1, 1920, pp. 118-120 (Library of Congress, gdc officialathletic13amat); reprinted from the same setting in the edition in force January 1, 1921, pp. 122-124 (officialathletic12amat). Public domain.