The first char is likely to take several times as long to level as the rest of them... that's my experience with the beta after each wipe, anyway... no twinking, no gold bank, no stash space, no artisan. And, of course, you'll be exploring with no idea what to expect or what the optimal search patterns are, and spending time staring at your inventory comparing items, and reading skill and rune descriptions. So the first char is the one you'll be spending the most time with

Should be one you enjoy!
Bookmarks