The elite monster will fail to spawn in with no error message if the map is at the hard capped population at the moment the rune is activated.
To avoid this, kill a lot of monsters and activate the rune before the map reach it hard capped population again.
(Soft cap population is the regular max monster without fury/kishin/frenzy, hard cap is achieved with fury/kishin/frenzy)
If another skill can be buffer during a skill or the skill can be animation cancel into another skill, it count as skill linking.
(Buffer as in if you press another skill during a skill, it immediately use the next skill as soon as the previous skill is over)
All variation of familiar drop rate and meso drop rate that appear as a buff in the top right corner
(Increases Meso Drop Rate by a small amount
Increases Meso Drop Rate
Increases Meso Drop Rate by a large amount
Increases Item Drop Rate by a small amount
Increases Item Drop Rate
Increases Item Drop Rate by a large amount
Increases Item and Meso Drop Rate by a small amount
Increases Item and Meso Drop Rate
Increases Item and Meso Drop Rate by a large amount)
are treated as unstackable buff (cannot stack with any other version unstackable drop rate/meso buff) (There exist certain drop rate coupon that are coded differently such as legion luck lv1/2/3 that will stack with familiar drop rate buff, but any other one need to be tested on a case by case basis)
Only the highest amount is applied if you have multiple item/meso drop rate familiar potential. (even if the buff icon show all the meso/item drop rate buffs through a specific order, only the highest amount is applied)
Item Acquisition Rate: +10/12% can be stacked infinitely (well 6 times) because it is a copy of the equipment potential version (not affected by the +200% equipment potential drop rate cap)
In general, any familiar potential that appear as a buff in the top right corner is unstackable with any version of itself or any unstackable buff.