Pets should be taking 75% of the xp if no one does damage (and 0% of the xp if someone does do damage) if we want to use the ruleset from 2002 which is the closest to how it is currently.
However, we should probably also add the other pet changes (no mobs agroin on pets that walk past).
http://www.tski.co.jp/baldio/patch/20020605a.html
Code:
With this patch we've made some rather sweeping changes to the way pets work.
Pets will not attack mesmerized creatures. Pets basically treat mesmerized
NPCs as if they were dead.
Pets are neutral to NPCs. Monsters will not attack pets first unless the pet is being
aggressive to something.
Pets take 75% of the experience from a creature if no player does damage to that creature.
Pets take ZERO experience from a creature unless no player does damage to that creature.
The exception to the above rule is Dire Charmed pets, which will take a share of the
experience scaled by the amount of damage they do. In most situations (with an
active party, for example) the Dire Charmed pet will not take experience. Like all
pets, they will take 75% of the experience if no PC does damage to the target. As
long as a player does damage to a creature, a Dire Charmed pet will never take
more experience than it used to.
Charmed NPCs will now respond to the /pet report health command.
/pet sit down command should now work on charmed NPCs.
Fixed a bug that was preventing reclaim energy from working on Magician Epic pets.
But to really match the timeline, pets should not take any XP, and to combat AFK experiencing while a necro is AFK, we need the following change from earlier in our own timeline (adding a limited duration to necromance Feign Death):
Code:
The "Feign Death" spell, when cast by a Necromancer, will now have a fixed duration.
The Necromancer will receive several warnings prior to the spell wearing off. This change
was necessary because some Necromancers found a way to gain experience through
their pet while being AFK for an extended duration, such as being in bed for the night.
Note: This does not affect Shadowknights or Monks.
Sourced from:
http://www.tski.co.jp/baldio/patch/20000217a.html
^^^ The above necro comment also indicates that it WAS entirely possible to AFK xp as a pet class (and no risk as a FD'ed necro)