How does mob drop item actually work?

[astroNOT 153]

So lets say I have this mob drop for 8027, lvl 90 stone

 

Group	전운석
{
	Mob	8027
	Type	drop
	1	151	1	3
	2	152	1	12
	3	153	1	8
	4	5091	1	5
	5	5092	1	15
	6	5093	1	10
	7	141	1	5
	8	142	1	15
	9	143	1	10
	10	3131	1	10
	11	3132	1	15
	12	3133	1	20
	13	1101	1	10
	14	1102	1	15
	15	1103	1	20
	16	7131	1	10
	17	7132	1	15
	18	7133	1	20
	19	2141	1	10
	20	2142	1	15
	21	2143	1	20
	22	11681	1	10
	23	11682	1	15
	24	11683	1	20
	25	11881	1	10
	26	11882	1	15
	27	11883	1	20
	28	11481	1	10
	29	11482	1	15
	30	11483	1	20
	31	11281	1	10
	32	11282	1	15
	33	11283	1	20
	34	17164	1	9
	35	17165	1	24
	36	17166	1	14
	37	11490	1	3
	38	11492	1	8
	39	11493	1	10
	40	11290	1	3
	41	11292	1	8
	42	11293	1	10
	43	11690	1	3
	44	11692	1	8
	45	11693	1	10
	46	11890	1	3
	47	11892	1	8
	48	11893	1	10
	49	27992	1	3
	50	27993	1	3
	51	27994	1	3
	52	14201	1	5
	53	14202	1	10
	54	14203	1	15
	55	16201	1	5
	56	16202	1	10
	57	16203	1	15
	58	17201	1	5
	59	17202	1	10
	60	17203	1	15
	61	15201	1	5
	62	15202	1	10
	63	15203	1	15
	64	13060	1	5
	65	13061	1	10
	66	13063	1	15
	67	13080	1	5
	68	13081	1	10
	69	13083	1	15
	70	13100	1	5
	71	13101	1	10
	72	13102	1	15
	73	13120	1	5
	74	13121	1	10
	75	13122	1	15
	76	17107	1	5
	77	17108	1	10
	78	17109	1	15
	79	101	1	100
}

For this drop settings, it drops 1-2 items, sometimes none, very rare 4-5 items, but ~never more

Whats the logic here, how does this work, why isn't like 79 always given when the stone dies?

[Syreldar 1847]

14 hours ago, astroNOT said:

why isn't like 79 always given when the stone dies?

Because the number you see represents a quarter of the real drop percent.

If you want an item to always drop, its drop pct should be 400, not 100.

[Mitachi 1402]

Well, I did something to remember this in the past, as @ Syreldar said, the Type drop is actually 400% oriented.

There are more than 3 types counting thiefgloves, but the mostly used are these 3:

1. Type    drop
2. Type    level_limit
3. Type    kill_drop

 

Type drop (really common)

#1.	Type	drop
	He hasn't a 100 pct, but 400 pct

[*] > Example:

Group	Example_Type_Drop
{
	Mob	101
	Type	drop
	1	19	1	400 -- 100%
	2	29	1	32  -- 8%
}

 

Type level_limit (used usually for certains monsters, like Deathripper)

#2.	Type	level_limit
	He have a 100 pct.
	The limit determines which level you can get the item from

[*] > Example:

Group	Example_Type_Level_limit
{
	Mob	2071
	Type	limit
	level_limit	60
	1	19	1	100 -- 100%
	2	29	1	32  -- 32%
}

Type Kill_drop (really rare, used for monkeys only I guess)

#3.	Type	Kill_drop
	He have a 100 pct, the peculiarity is:
	You can determine after how many monsters you have the % to drop the item.

[*] > Example:

Group	Example_Type_Kill_drop
{
	Mob	5162
	Kill_drop	10 -- Every 10 mob, you have the% to get the item
	Type	drop
	1	19	1	100 -- 100% prob(Every 10 mob)
	2	29	1	32  -- 32% prob(Every 10 mob)
}

[astroNOT 153]

Thank you so very much @ Syreldar and @ Mitachi!

I and probably the community are very grateful for such useful explanation!