In golf, there's a maximum number of golf clubs that a golfer can carry in their bag.
A golfer is allowed to carry fewer than that maximum number of 14 golf clubs, but at no point in a round can a golfer have more than 14 clubs in their bag -- even if they have no intention of using some of them during a round.
If a player realizes they're carrying too many clubs in their bag -- or their playing partner or opponent notices that they're carrying too many clubs in their golf bag -- then the penalty is pretty steep. In fact, the penalty is one of the most punitive in golf short of disqualification.
What's the penalty for carrying too many golf clubs in your golf bag?
In stroke-play golf events, the penalty for carrying too many clubs in your golf bag is two strokes for each hole during which you've carried too many clubs in your bag (at any point during the hole). The maximum penalty is four strokes under Rule 4-1.
Hypothetically, then, a player could compete with more than 14 clubs for the entire round, perhaps with their knowledge, and only have a maximum penalty of four strokes. If, for some insane reason, a player decides they need more than 14 clubs during a round, they could clandestinely have extra clubs in their bag and use them all while getting, at most, a four-stroke penalty. It's hard to see a scenario where it would be worth it to incur a four-stroke penalty, but crazier things have probably happened.
The incentive to carry too many clubs in match play, though, is simply not there. In match play, the penalty for carrying too many golf clubs is a match-adjustment penalty. For each hole during which a player had too many clubs in the bag, that player loses the hole -- up to a maximum of two holes. Losing hole outright would not be worth cheating.
Even if game theory comes into play for some golfers, all golfers would be well advised to only carry 14 clubs in the bag during a round.