Talk:Jumbo the Elephant

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Meeting Jumbo

Ihave never encountered Jumbo. What are the odds of encountering him in any given game. Is there any way to improve those odds?--Ndwolfwood 06:13, 22 December 2010 (UTC)

The only way I can think of to increase the odds of meeting Jumbo is to increase the number of real zoos. Real zoos only appear after dungeon level 9, but if you skip over a level (e.g. by controlled levelport) and never enter the level before acquiring the amulet of yendor, the level will be generated as if it was an extremely deep level. I've seen it happen in wiz mode with traps (e.g. a polytrap on level 2), and I imagine it would still work with special levels. -- Qazmlpok 14:16, 22 December 2010 (UTC)
Quazmlpok's method works on levels 1-6.
You can also genocide/extinct leprechauns, soldiers, and killer bees before entering a new level. That way leprechaun halls etc. won't be generated, and the level retains its chance of getting a zoo. (Mklev.c#line733, SLASH'EM_0.0.7E7F2/mklev.c#line766) --Tjr 15:14, 22 December 2010 (UTC)

Probability of appearing

I actually sat down and wrote a little Python snippet to simulate this guy's chances of appearing:

import random
for lvl in range(39,46):
    jumbos = 0
    for i in range(20000):
        if random.randrange(0,11) == 0:
            if random.randrange(0,60) + random.randrange(0, 3 * lvl) > 175:
                jumbos = jumbos + 1;
    print(lvl, ",", jumbos/20000)

Running this a few times gets results that basically never exceed .25% for the deepest possible levels, with the probability exponentially decreasing for higher ones. That makes him *extremely* rare: at best you've got like a .4% or .5% chance of seeing him, and for every level that the Castle is above D:47, that probability is decreased by another 40% or so. -Ion frigate (talk) 10:13, 2 August 2023 (UTC)

And it turns out I misread the code. That's per-monster, not per-zoo. Here's my updated snippet with some reasonable guesses for zoo size:
import random
for lvl in range(39,47):
    jumbos = 0
    for i in range(5000):
        if random.randrange(0,11) == 0:
            zoo_x = random.randrange(2,10)
            zoo_y = random.randrange(2,6)
            for i in range(0, zoo_x * zoo_y):
                if random.randrange(0,60) + random.randrange(0, 3 * lvl) > 175:
                    jumbos = jumbos + 1;
    print(lvl, ",", jumbos/5000)
Basically guessing that zoos are 2x2 to 5x9; running this, you have something like a 5% chance on D:46, 4% on D:45, 3% on D:44, 1.5% on D:43, and <1% on lower levels. Given that the main dungeon doesn't reach down to D:45+ that often, it still makes sense that you could play dozens or hundreds of times and never see this guy. -Ion frigate (talk) 18:58, 4 August 2023 (UTC)

You mean "higher" levels, in regards to DL? --Umbire the Phantom (talk) 19:23, 4 August 2023 (UTC)

Yes, that is what I meant. Was thinking "lower-numbered levels", but I guess describing the physical location (higher) is more common. -Ion frigate (talk) 20:22, 4 August 2023 (UTC)