Number of Players

Year (Source) new or changed laws (proposing club, if known)
Diverse reports about football matches before 1870 There wasn’t a written regulation how many players of a team had to participate in a game at the same time and how many were allowed to do so. There were the variants with eight players and with eleven players or only the requirement that there must be an equal number of players on both sides. At least in the FA, however, the variant with eleven players seems to have been usual.
1849, Surrey FC Eleven players.
1857 (Sheffield FC) No information.
1897 (IFAB) Eleven players.
1921 (IFAB) If a player wishes to enter the field after the match has started, he must report himself to the referee (FA).
1924 (IFAB) If in the opinion of the referee a player is seriously injured, he shall stop the game so that the player can be removed from the field. If the player is slightly injured, he doesn’t need to stop it until the ball is outside the field (SFA).
1978 (IFAB) If a free kick is awarded to a team in its own goal area, the free kick may be taken from any point within the goal area (FA).
1997 (IFAB) A player with a bleeding wound may not continue playing and must leave the field for treatment.
2002 (IFAB) An injured player who has been medicated may not return to the field until the match has been restarted (FIFA).

 

Proposals for law amendments that were not accepted:

year club/association proposal reaction
1924 SFA If a player is injured, the game is not interrupted until the ball is off the field. Then the injured player is removed from the field and the game is restarted. withdrawn

 

 

Number of substitutions

Year (Source) new or changed laws (proposing club, if known)
1923 (IFAB) In non-competition matches, teams may agree to replace injured players with others before the match (FA).
1951 (DFV) The DFV (Football Association of the GDR) allows substitutions of goalkeepers and field players. The GDR is not a member of FIFA and can therefore venture this experiment. It is also valid in the following season. – Thank you very much, @fussballDDR!
1953 (IFAB) No player was allowed to be substituted during the match until this year. Only if it was not a competition match, the clubs could negotiate with the referee before the match that injured players could be replaced.
1953 (IFAB, international games only) Since the qualifying for the 1954 World Cup, it was allowed to substitute players in competition games. But only in case of injury and only one player per team and match.
1957 (IFAB) Each national association can decide for itself whether to allow substitutes in the event of injury or not (IFAB).
1965 (FA, possibly DFB as well) This law was adopted for national competitions, presumably also by the DFB. The substitution could only be done during a game interruption.
1966 (FA, possibly DFB as well) Substitutions (one game per team and per game) can now be made independently of an injury.
1967 (IFAB) In friendly matches, up to two players per team may be substituted independently of an injury, provided that the national football association permits substitutes. Before the match, the namens of the substitutes must be known by the referee. If a player is excluded from the match before the begin of it, he or she may only be replaced by one of the named players. A substitute player expelled before or during the match may not be replaced. The referee must be informed of a substitution and the substitute player may enter the field only during an stoppage in the game and with the referee’s permission. A substitute is also a player under the jurisdiction of the Referee (IFAB).
1968 (IFAB, also national games) Substitutions of up to two players per team and match are possible regardless of an injury.
1971 (IFAB) The two substitutes must have been selected from five previously nominated substitutes.
1972 (IFAB) No maximum number of substitutes in friendly matches, but mutual agreement. A maximum of two substitutes may be substituted in competition matches; a maximum of five substitutes may be nominated and their names must be notified the referee prior to the match (FA).
1972 (IFAB) Substitutes leave the field at the middle line (WAF).
1973 (IFAB) The substitute may enter the field after the player has left it (SFA).
1980 (IFAB) A player who has been substituted loses his or her status as a player when the substitute enters the field and may not be substituted again (FA).
1980 (IFAB) If a substitute has not previously registered by the referee, he or she will be cautioned or sent off, depending on the circumstances. The match is restarted by the referee dropping the ball at the place where it was when he stopped the play. (FA).
1981 (IFAB) If a substitute enters the playing field without permission, he or she is cautioned and must wait for the next interruption of play.
1985 (IFAB) If a substitute has not previously registered with the referee, the match shall be stopped immediately and, restarted by a dropped ball at the place where the ball was when play was stopped. Addition: Unless the ball was in the goal area at that time, in which case it will be dropped onto that part of the goal area line that is parallel to the goal line, at the point closest to where the ball is located, as in the case of interruption of play (IFA).
1987 (IFAB) Each competition may determine the number of substitutions allowed (FA).
1994 (IFAB) The number of allowed substitutions will be increased to „2+1“, i.e. two field players and one goalkeeper (FIFA).
1995 (IFAB) The „2+1-law“ will be changed slightly. Now three substitutions are possible, regardless of whether the players are field players or goalkeepers. Still, the referee must be informed by their names (SFA).
1996 (IFAB) For each competition, the number of substitutes that may be nominated before the match must be determined and must be between three and seven (FAW).
1997 (IFAB) Up to five substitutes may be nominated for competition matches.
2000 (IFAB) In non-competition matches, the two teams can agree on the number of substitutes before the start of the match. The referee has to be informed (SFA).
2004 (DFB) For friendly matches, three to twelve substitutions per match and team are possible.
2015 (IFAB) Optional for the national associations: Withdrawal of substitutions (only for amateur players). This has been successfully tested for two years in the FA and SFA. The participation level of players increased significantly. Furthermore, it stopped teams from dropping out mid-way through the season and also helped players coming back from injuries by managing their game time better (FA, SFA)

 

Proposals for law amendments that were not accepted:

year club/association proposal reaction
1948, 1949 SFA If a goalkeeper is injured, he or she may be substituted. However, the substitute player is not forced to take the goalkeeper’s position. rejected
1955 SFA No player may be substituted in competition matches. The goalkeeper may be substituted if he or she is injured. withdrawn
1956 SFA No player may be substituted in competition matches. rejected
1956, 1957 FIFA The goalkeeper may be substituted if he or she is injured, but in competition matches the substitute player may only undertake the goalkeeper’s position. rejected
1966 FIFA Each team consists of 13 players. 11 of them play (one as goalkeeper). The two remaining players may replace any player of the eleven once during the match. A dismissed player may not be replaced. withdrawn
2015 FIFA (CONMEBOL, Sri Lanka and US Soccer) A fourth substitution per team, which is possible in extra time of a match. rejected