Guide Experience in D2 - A mathematical perspective

Most D2 players follow a simple standard recipe for exp-ing: get a rush to hell ancients, hell Baal optionally, then go BH-ing, public (most) or private (some).
This guide is meant to offer a slightly different perspective on things. It relies on being able to launch 8 game windows by yourself.

Prerequisites:
1. Eight accounts, one char in each account, of which 7 g-rushed to Hell, at least one to act 4. The main char should also be g-rushed, getting Baal quests in each difficulty, but not the Ancients quests (more details on this a bit later).
A main char that is able to kill fairly quickly and not freaking die.
2. Full gear for the main char, including torch and anni (10% exp gain to be preferred). full merc gear.
3. Working maphack (you may smile, but try doing it without) and patience, a lot of it.

Some theoretical background
Basics
Very briefly here:

• you get exp for every mob that you / your merc / a party member kill(s) (if you're within 2 screens of the mob killed)
• for mobs that are within the [Clvl - 5, Clvl + 5] interval, you get full experience; for mobs that are 10+ levels below / above your Clvl, you get 5%; for mobs between 6 and 9 levels below / above your Clvl, penalties apply and you can find it all here - http://classic.battle.net/diablo2exp/basics/experience.shtml
• furthermore, there are additional penalties that apply from Clvl 70 upwards, the table is available at the same link
  Note 1: for Clvl 70+, both penalties apply, if the case
  Note 2: for our server, you get 10x exp for Clvl 1-70, 5x for 71-85, 3x for 96-91 and 1x when you hit Clvl 92, that's when exp gain returns to normal, i.e. slows down bigtime.
• for multiplayer games (which is our concern), this formula applies:
  
  This means that, for a 8 player game, mobs will have X * (8 + 1) / 2, that is X * 4.5, that is 4.5 times their base experience
• Exp shrines give your char +50% exp gain, for 144 seconds, that's 2 mins and 24 seconds. The 50% gain is added to your other exp gain sources - items or party members in the same area. Contrary to what some people believe or state, a player with an active exp shrine, in a public BH, is not leeching; he is only increasing his exp gain for as long as the shrine is active, albeit he is not taking part into killing in the Throne room.
• To calculate experience from a killed monster, all bonuses are added from all sources and the total, Y%, is added to the experience by the formula:
  Exp = X * (100 + Y) / 100, where X is the HP of the mob killed. The formula works very similarly to how enhanced defense (ed%) is calculated, some practical examples will follow below.
• last, but not least, a quote related to monster experience, which is of relevance for this guide
  
  - http://classic.battle.net/diablo2exp/monsters/bonus.shtml

The juice / icing on the cake

1. Translation: if your char has a party member in the same area (ex: Chaos Sanctuary, River of Flame, etc.), (key element) even a dead one, your char receives an extra 35% experience
2. This highlighted part of the quote is where I got the main idea for this guide, so a short explanation, with examples, is due here.

Simple case:
We have 8 players, all 93, all partied and in Throne room. A minion of destruction (5th wave) is killed, everyone is in range. HP = 150000 (for ease of calculation - http://classic.battle.net/diablo2exp/monsters/act5-baalsminion.shtml).
We have: 150000 * 4.5 = 675000 (8 player game); 675000 * 5 = 3375000 (x5 for being a minion, and not by name) - this is base exp.
Now, to how it is divided: we have 93 + 93 +....+ 93 = 744 (8 * 93) as divider. Each one player receives 93 / 744 = 1 / 8 of the total share, that is 421875 base experience.
Assuming each player has torch + 10% anni in inventory, we have the following exp bonuses: 5% (torch) + 10% (anni) + 35% (party member in the same area) = 50% exp bonus. This means that each player will receive 421875 * 1.5 = 632812.5 experience.
Looking good, huh? Now it's time for penalties .
Clvl - Mlvl is 93 - 88 = 5, so no penalty for this difference.
But here comes the big truck: from the fancy looking table in the Experience page from Blizzard, we find out that for Clvl = 93 we need to apply a 2.54% "adjustment" to the experience. Our 632812.5, adjusted by 2.54%, now turns into 16073.43. Not looking so good now, ey?

Complicated case:
Again 8 players, {98, 96, 92, 89, 88, 88, 75, 69}. The 89 lvl player stays in town and eats popcorn, so no exp for him, just popcorn. Again a minion of destruction, so the same calculations for base exp - 3375000 total exp.
Sum of player levels - 693.
Lvl 98 player - same bonuses as above + active exp shrine, so 50 + 50 = 100% exp bonus. He gets 3375000 * 98 / 693 * (100% + 100%) = 954545 total exp (his share), before penalties. Clvl - Mlvl is 98 - 88 = 10, so he gets 5% of total exp, first adjustment, that's 47727. Then the penalty for Clvl, from the infamous table, is 0.59% for 98, so 281 final exp gain for our char.
Lvl 88 - 5 / 10 / 35 exp bonuses, no penalty for Clvl - Mlvl, 10.55% Clvl adjustment, so 3375000 * 88 / 693 * 1.5 (150%) * 10.55% = 67821 final exp gain.
Lvl 69 - 35 exp bonus, 5% penalty for Mlvl - Clvl > 5, no penalty for Clvl, so 3375000 * 69 / 693 * 1.35 (135%) * 5% = 22682 final exp gain.

I gave just a few examples to illustrate calculations, you can probably figure them out for any particular case.

A time to make a choice
If your aim is to level up one or more chars, there are few available ways one could go.
1. The traditional way, with all quests and Baal runs
2. Saving the Ancients quests for Clvl = 98, which can be achieved through a g-rush (this idea was borrowed from another guide).
Why? Because the reward for the Ancients quests is experience, whichever is the lowest of 1 character level or Normal - 1.5 mil, NM - 20 mil, Hell - 40 mil exp. Whoever has achieved high character levels, knows how time-consuming is to take a char from 98 to 99 (thousands of Baal + Diablo runs).
Here, there are 2 sub-paths that one could take:
2.a. Keep normal and NM ancients, but do Hell ancients and join public BH runs all the way; this way, you'll have 21.5 mil exp as a head start from 98.
2.b. Keep all ancients quests for Clvl = 98, and only do Diablo (+ Nihlathak runs, optionally). This way, you'll have 61.5 mil out of 291 mil exp, when going from 98 to 99 (some 21% or one fifth of the total time / effort). This sub-path is the focus of this guide's core idea.
Of course, there is a big trade-off involved. If you do Hell ancients, you can join public BH runs or do them by yourself (or with a buddy), but cover for the 40 mil exp when turning 98. Or, keep the Hell ancients for 98, but then you'll be restricted to Diablo runs till you hit 98.
Some advice and tips related to exp gain and DON'T-s will be mentioned toward the end of this guide.

And now the hardcore of this guide
In all honesty, I've read a bunch of materials on exp gain, various sites, but nowhere did I find what I'm presenting below. There are other ideas that will be presented towards the end of this guide, that I've "borrowed" (or "researched") from other guides, though.
What if I wanted to level one character, all the way to 99? I'd have the "traditional" approach - rush to hell + public bh-ing, thousands of runs, or .....
Or use math to drastically decrease the number of runs needed for the same goal. But how? - you'd ask.
Here's how: remember the little quote highlighted in green? What if we had, as a divider, when calculating the "exp loot" for each char, instead of 93 + 93 + 93 + 93 +93 + 93 +93 + 93 (= 744), let's say 93 + 1 + 1 + 1 + 1 + 1 + 1 + 1 (= 100). Or, in percent, 93 / 744 = 1 / 8 = 12.5% of total exp, in the first case, versus 93 / 100 = 93%, in the second case.
WOOt? you'd ask. Well, you have read very well, 93% of total exp pool instead of 12.5% on average, in public runs.
But how, master? you'd ask. Sit down, take a pencil and a piece of paper and write !

Remember the first prerequisite? It was 7 chars (one in each account), all g-rushed and all level 1, plus a main char also g-rushed, then leveled in Chaos Sanctuary. Why 8 accounts? Because I find that using 2 chars under the same account is annoying, when creating a new game, because you get kicked out in at least one game window (only 1 per account stays logged in, the one logged in the latest). I just find it simpler like that, but it's a matter of personal preference.
The MO (modus operandi) is simple: I do River of Flame, Chaos Sanctuary and Nihlathak in the same run, sometimes with variations in other areas. I TP, then get one lvl 1 char in (all other 6 stay in town, in act 1 permanently), get it killed by a mob (so it doesn't gain experience, which happens extremely fast), then start killing with the main char. Repeat when moving to the other area (only doing this for River and Chaos). Why do I do this? To gain the +35% bonus for a party member in the same area (dead one, but still a party member); this can be further increased by using exp shrines from act 1 (here Sting maphack comes in really handy), but the trickiest part is to avoid curses from oblivion knights (OK's) or other cursed uniques.

To sum up, you can gain roughly 90+% of the total exp pool (before penalties for Clvl), using 8 loader windows, with one main char able to kill fairly quickly and 7 lvl 1 chars, of which 6 will idle in town and 1 will be sent to die a useless death a few times every game.

Time has come to wrap up this guide (thanks for being patient enough to read it) with some tips.
TIPS:

• go for a char with max block, it helps a lot with staying alive and moving forward with exp, albeit slower
• whenever possible, go for eth e-bugged helm / armor / shield; high defense means getting hit much less often
• you could join with a BO barb, cast stuff, then rejoin with lvl 1 char (much better and safer option that CtA)
• go mostly for unique packs, possibly champ packs, exp gain is better this way
• additional sources of experience could be Uber Tristram, but be highly careful with Lilith and Uber Mephisto especially; also have a UT-killing char (smiter usually) that can really tank, keep your exp char in the back, but within 2 screens
• other mobs worth killing (I've done my own research here) are: Horadrim Ancients (next best exp after Minions of destruction) in WSK 2 and Throne, plus the Guardian variant in Halls of Pain; Death Lords - WSK 3, Blood Lords - Crystalline Passage; worthy mentions for Venom Lords, Oblivion + Doom Knights, Urdars
• you could find a mate to do runs with, you gain a partner and run speed, but lose roughly half of the exp pool; up to you in the end

DON'T-s:

• Don't trade survival ability for kill speed, fancy gear or God knows what else
• Don't die. From my experience, it is painful, especially at high levels. Best case scenario, when you recover your corpse in the same game, you lose 5% - 2.5% penalty for dying and another 2.5% to make it back where you were. Much worse if you don't recover corpse in the same game, for example by exiting the game accidentally. A total clusterfuck if you try to recover your corpse and die in the process, multiple times.
• Don't rush into mob packs
• Don't idle on the map, with mobs nearby. My chars have died several times this way. TP and idle in town.

Other tips may be added along the way, but for now thanks for reading and looking forward to your feedback.

 

Nice guide. Only there is something wrong with the math.

Try it yourself:
-Create new lvl 1 sorc, create game.
-Go out of rog camp, shoot one fallen - gives 180 exp.
-Create another new lvl 1 sorc, join the same game, don't get into party.
-Go out of rog camp, shoot one fallen - gives 180 exp.

So, if this:

Experience = X * (n + 1) / 2

is true, the second kill should give 270 exp. And it does not.

 

I tested it myself in a party, it works fine. I just don't get the reason. Why? On the official realm, I hijacked hell Baal in rush games of other players, I got all the great exp, and I am pretty sure, I was doing that off-party. What do I miss?

 

Want to share a bit of my own experience of lvling 90+ till 98 with my Nova sorc.

General:
Stats:
0 str/agi/vita
100500 energy

Skills:
1 point to: warmth, frozen armor, charged bolt, lightning, chain lightning, teleport, energy shield, thunder storm (optional)
20 points to: static field, nova, lightning mastery, telekinesis
remaining - lightning/charged bolt/chain lightning

Gear:
Obsession (swap on oculus for vigor and any shield with +10 str, will understand why if try it ), griffon's with Lo rune, Sorc TM, mara, arah, 2 soj, frostburn, SandStorm Trek, Anix, Torch, Skillers (i use 14 skillers, some with +life and Gheeds to leave some space for loot).

Party:
6 mules + BO barb (with skillers) and maxed Increase speed

My route:
I loot all the gems/jewels/GCs/SCs, unique charms/rings/other good stuff which takes 2-3 min, which you can giveup to fasten exping.
I start with any WP and tp for my BO barb (13+ minutes of BO/BC/Shout). Whole route considers 13 minutes BO, if you are quicker than WildWest cowboys - you can add any additional 85 lvl area.
General rule - we kill only uniques (no champions or any other creeps) and try to be effected by exp shrine (2min 24 sec each). I just rush into middle of the pack and cast nova (only 1 exception - scaring Dolls...), BO with ES allows to survive without almost any lose of HP.
1. 3 act - Travi: rush into and kill everyone with nova (thats not exp but a little chance for Gheeds drop to have chance for 94-99 GC)
2. 1 act - Pits 1-2: just kill all uniques (not champs). P.S. while teleporting searching for exp shrines
3. 3 act - ruined temple (kurast bazar)
4. 5 act - abaddon (frigid highlands), pit of acheron (arreat plateau), infernal pit (frozen tundra)
5. 4 act - river of flame (part from wp to Chaos sanctuary) and Chaos sanctuary
6. 5 act - nihlathak, WSK 2-3 (i don't go 1) and Throne with Baal.

Result:
Time: 10-13 minutes (and i'm not fastest hands ever )
Exp received on 97 lvl (i'm here and is only result i can share this moment): 1.2-1.7kk (depends on exp shrines)
Loot: 100% your's.

P.S. just going BH on 97 lvl:
Time: 3 minutes
Exp received: 0.17kk (0.22kk with shrine)
Loot: 12.5% yours

P.P.S. yes, you do all the "job" on your own but receive all the benifits instead of tasting your Latte and cast blizzard from time to time.


In case of any errors or issues, tag me

Some screens: