2.6 Experience points
 
Each time you kill a monster you have a chance of receiving experience points. You receive experience for killing a monster as long as your own level is below the mlvl+10 (see chapter 5.2 and 5.6.3 for more information about mlvl and experience points). In multi player, each person that fulfills one of following requirements is entitled to receive experience points when a monster is killed.

• Killing the monster (both in melee and with spell).
• Dealing damage to the monster in either melee or with a bow (regardless of any extra fire or lightning damage even if the monster is resistant or immune to it).
• Dealing damage to the monster with a spell to which the monster is not resistant or immune.
• Having your golem kill or deal damage to the monster.
• Having used Telekinesis on the monster (Snotspill, Gharbad the Weak, Zhar the Mad, Warlord of Blood, Lachdanan, Arch-Bishop Lazarus, Blackjade and Red Vex are all immune to Telekinesis though).

In all cases you must be alive at the moment the monster dies and you must never have left the level in-between fulfilling any of the requirements above and the monster dying, or you will not receive any experience points. The requirement of dealing damage is fulfilled even if for some reason the damage itself is reduced to below 1 point of damage (theoretically even 0 damage will be enough). Stone Cursing a monster will not be enough to receive any experience points. A Guardian is treated as a normal fire spell for the purpose of deciding if the owning player is entitled to experience points. In Hellfire a Berserk monster will not give you experience points for the other monsters it kills.
 
In single player you are then rewarded the amount of experience points according to the formula below. In multi player the same formula applies, but the base experience points of the monster are first divided by the number of players that are entitled to receive experience points, which is not necessarily all players in the game.
base · (1.0 + 0.1·(mlvl - clvl))
 
So when your clvl is 10 levels higher than the mlvl, you no longer receive any experience for killing it. Base refers to the base experience points found in chapter 5.2 modified for the number of players that are entitled for experience points according to the explanation above.
 
The maximum experience you can obtain for killing a monster in multi player (both in Diablo and Hellfire) is 200·clvl or the total experience points needed for advancing to the next clvl divided by 20, whichever is the lowest. In single player there is no such a cap. With the added possibility of difficulty levels in single player in Hellfire along with no character level requirements for harder difficulty levels, you can get quite a lot of experience points when killing monsters. In Hellfire, there are also some shrines that affect your experience points (see chapter 7).