Cool, here's a few suggestions

• 1) Add use strict; and use warnings; to the beginning of every script. This will require you to declare all your variables with my which will help you avoid spelling errors in your code.
• 2) use CGI::Carp 'fatalsToBrowser': You simply misspelled fatalsToBrowser in your commented out line.
• 3) Don't use a file to save state at all, instead pass additional cgi parameters along with 'i'

Here's a quick clean up of your code with the above suggestions:

#!/usr/bin/perl

use CGI ':standard';
use CGI::Carp "fatalsToBrowser";

use strict;
use warnings;

my $i = 1 + (param('i') || 0);
my $firstroll1 = param('roll1');
my $firstroll2 = param('roll2');

print header;

my $dice1 = 1 + int rand 6;
my $dice2 = 1 + int rand 6;

print "($i) $dice1, $dice2<br>";

if (!$firstroll1 || !$firstroll2) {
    $firstroll1 = $dice1;
    $firstroll2 = $dice2;

    my $sum = $dice1 + $dice2;
    
    if ( $sum == 7 || $sum == 11 ) {
        print "you win";
        print qq{<hr><a href="dice.cgi">play again?</a>};
        exit;
    }
    elsif ( $sum == 2 || $sum == 12 ) {
        print "you lose";
        print qq{<hr><a href="dice.cgi">play again?</a>};
        exit;
    }
    
} else {

    if ($dice1 == $firstroll1 && $dice2 == $firstroll2 ) {
        print "match";
        print qq{<hr><a href="dice.cgi">play again?</a>};
        exit;

    } elsif ($dice1 == $firstroll2 && $dice2 == $firstroll1 ) {
        print "match";
        print qq{<hr><a href="dice.cgi">play again?</a>};
        exit;
    }
}    

print qq{<a href="dice.cgi?i=$i&roll1=$firstroll1&roll2=$firstroll2">R
+oll Again?</a>};
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