Old version:
When someone killed an enemy players in a certain radius got a small bit of xp and gold. A few hundred xp and 8 gold for high levels. This way you slowly accumulated experience and gold over a round, which was shown in the top right corner. If your team won you got that amount. If you lost you got like 25% of it. Gold and xp was a looooooooooooooooooot slower than nowadays.
This system required you too stick close to the main group to get your xp. So basically the two teams were two big blobs. You only got xp and gold for near kills if you were alive, although you still got it up until 30 seconds after your death. Staying close to the rest and staying alive was very important. Flanking meant getting barely any xp. This caused for the infamous XP barns.
http://www.youtube.com/watch?v=P32SuOJExR8Here you can see the old system in action. Shot at 27 may 2010, equipment is very peasantlike, cause people hadn't accumulated that much gold back then. I started playing in december, when plate was pretty much the norm, and people outarmoured, outspammed, outran, outdamaged me. Which is why this system wont work without regular full wipes.
There was no upkeep. You buy an item, you keep it and can use it at will. I remember getting 200 gold for a won round, was a very good round. So lets say average of a 100 taken into account losing and the 25% gain if you lost. A 20k destrier would take 200 rounds for you to save up.
There was no level limit. Leveling got harder with every level, but not like the current 30-35 leveling. There were lvl 42 players and maybe even higher.
You could retire once every week after you had reached lvl 15. First retirement cost like 10k, and got 10k more expensive with every retirement (not sure of these values at all). Retiring would grant you a 10%(?) wpf bonus next gen. If you had 150 polearm wpf before retirement. You would have 15 to start with or something like that. Basically with retiring you could continously increase your max wpf. Leading to 30 agi 250 wpf katana spammers. Katana was like 104/105 speed, which was pretty gamebreaking.
Thats all I can remember right now. Hope chadz enables the old version on a server again, so you can see for yourself.
B3RS3RK was first, damn, ah well might as well post this anyway.
Oh yes, no slot system. There were archers in heavy armour with a danish greatsword (sword of cookies) on their backs.