use strict;
use warnings;
use Data::Dumper;

my @players = (
    {
        name    => 'name1',
        deaths   => 2,
        kills   => 5,
    },
    {
        name    => 'name2',
        deaths   => 2,
        kills   => 5,
    },
    {
        name    => 'name3',
        deaths   => 2,
        kills   => 5,
    },
    {
        name    => 'name2',
        deaths   => 1,
        kills   => 4,
    },
);

my %merged;

foreach my $player (@players) {
    if(exists($merged{$player->{name}})) {
        $merged{$player->{name}}->{deaths} += $player->{deaths};
        $merged{$player->{name}}->{kills} += $player->{kills};
    } else {
        $merged{$player->{name}}->{deaths} = $player->{deaths};
        $merged{$player->{name}}->{kills} = $player->{kills};
    }
}

print Dumper(\%merged);