Club Sets
The rules of golf limit each player to a maximum of 14 clubs in their bag. Strict rules prohibit sharing of clubs between players that each have their own set (if two players share clubs, they may not have more than 14 clubs combined), and while occasional lending of a club to a player is generally overlooked, habitual borrowing of other players' clubs or the sharing of a single bag of clubs slows play considerably when both players need the same club.
The most common set of men's clubs is:
A driver, usually numbered a 1-wood regardless of actual loft, which varies from 8° up to 13°
A fairway wood, typically numbered a 3-wood and lofted about 15° (though 2- and 4-woods are sometimes seen)
A matched set of 7 numbered irons from 3 through 9, plus a pitching wedge or "10-iron"
A sand wedge
A putter
The above set is only 12 clubs; these (or equivalent hybrid substitutes) are found in virtually every golf bag. To this, players typically add two of the following:
Another fairway wood, often a 5-wood lofted around 18°, to allow other options besides long irons in the 180-250yd range
A hybrid, typically lofted for similar distance as a 3- or 4-iron and replacing those clubs in the bag.
A gap wedge, typically lofted 52° to fit between the modern pitching and sand wedges in loft
A lob wedge, typically lofted around 60° and used for tight approach shots from the rough or sand.
Women's club sets are similar in overall makeup, but typically have higher lofts and shorter shafts in retail sets to accommodate the average female player's height and swing speed.
The most common omissions are the "long irons", numbered from 2-5, which are notoriously difficult to hit well. The player can supplement the gaps in distance with either higher-numbered woods such as the 5 and even the 7-wood, or may replace the long irons with equivalently-numbered hybrid clubs. If hybrids are used, higher-lofted woods are often omitted as redundant, but ladies and seniors sets commonly feature both hybrids and high-lofted woods, omitting the long irons entirely in favor of the lofted woods, and replacing the mid-irons (5-7) with hybrids. The combination allows for higher launch angles on the long-distance clubs, which gives better distance with slower swing speeds. Where a club is omitted and not replaced with a club of similar function, players may add additional clubs of a different function such as additional wedges.
While 14 clubs is a maximum, it is not a minimum; players are free to use any lesser number of clubs they think will be useful, so substitutions for the common omissions above are not always made; a player may simply choose to play without a 5-wood or 2-4 irons, instead using a 4-wood and moving directly to their 5-iron as desired distance decreases (a 4-wood in a skilled golfer's hands averages 200 yards; a 5-iron in the same player's hands would be about 160, which is a large gap but not unplayable).
While 14 clubs is a maximum, it is not a minimum; players are free to use any lesser number of clubs they think will be useful, so substitutions for the common omissions above are not always made; a player may simply choose to play without a 5-wood or 2-4 irons, instead using a 4-wood and moving directly to their 5-iron as desired distance decreases (a 4-wood in a skilled golfer's hands averages 200 yards; a 5-iron in the same player's hands would be about 160, which is a large gap but not unplayable). Other clubs may be omitted as well. On courses where bags must be carried by the player, the player may take only the odd-numbered irons; without the 4, 6 or 8 irons (the 3 is sometimes removed instead of the 4) the bag's weight is considerably reduced.
Carrying only a driver, 3-wood, 4-hybrid, 5-7-9 irons, pitching and sand wedges, and a putter reduces the number of clubs in the bag to 9; this is a common loadout for a "Sunday bag" taken to the driving range or to an informal game. A skilled player can usually overcome the lesser selection of club lofts by reducing their swing speed on a lower-loft iron and/or placing the ball further forward in their stance to get the same carry distance and/or launch angle as the next higher loft number.
Variations on this basic set abound; several club options usually exist for almost any shot depending on the player's skill level and playing style, and the only club universally considered to be indispensable is the putter.