Releasing in 2018, Red Dead Redemption 2 offers players an open world set against the backdrop of the United States in the 1800s. As protagonist Arthur Morgan, players could do just about anything in the water - from swimming and fishing to steering a boat. Arthur Morgan can easily swim across a river, but John Marston can't. There's actually a pretty good reason why John Marston is such a bad swimmer.
The main character of the first Red Dead Redemption, John Marston, also reappears as a playable character in its prequel. Much like in the first game, John can't swim very well in Red Dead Redemption 2. While Arthur Morgan can make it across the river just fine, John Marston will be lucky to make it past the shore. If John jumps in a lake or river, his stamina bar will deplete almost instantly, and he'll drown.
John's swimming skills (or lack thereof) have spawned many jokes within the Red Dead Redemption fandom. It can be especially funny, or frustrating, if John drowns during a simple fishing session. While it may seem odd for a character to be so terrible at something like swimming in an open world game, there's actually a good reason for this. It all stems from the fact that John Marston couldn't swim in the original Red Dead Redemption game either.
Why John Marston Can't Swim In Red Dead Redemption
John Marston's terrible swimming skills are actually a callback to a Red Dead Redemption gameplay limitation, which didn't let players swim at all. Early open world Rockstar titles like Grand Theft Auto 3 and Vice City did not allow players to swim either, but later games such as Grand Theft Auto: San Andreas and Grand Theft Auto IV did. In the first Red Dead Redemption title, this feature was most likely excluded to keep players from swimming to areas like Mexico too early. Rockstar Games kept the concept for John Marston being a bad swimmer for Red Dead Redemption 2. It's a hilarious nod to to the first game, and it's also considered canon now.
Canonically, John Marston just never learned how to swim. This explains why something as simple as jumping in a lake can be deadly for John in Red Dead Redemption 2. Since John couldn't swim in the first game, and RDR2 is its prequel, it stands to reason that John wouldn't know how to swim then either. There's no big secret as to why John Marston can't swim in Red Dead Redemption 2. Surprisingly, it's just that he never learned how. It's also a nice callback from Rockstar Games to explain the swimming limitations in the first Red Dead Redemption.