ASI increases damage received by tinies
Because they are so delicate it is advisable to keep your tiny friends in your inventory where they are safe from the dangerous outside yes maybe even in a jar but put some wool in it for it to be cosy
By default, tinies will receive more damage the smaller their scale, this can be disabled in the Server Config:
actuallysize-server.toml
# This enables this feature in which tinies receive increased damage
tiniesAreDelicate = true
# This disables this feature in which tinies receive increased damage
tiniesAreDelicate = false
This deals with environmental sources of damage, where another entity is not attacking you — essentially lava, fire, lightning, anvils, etc. The list is pretty large when you actualy get into it. A special case is fall damage, since ASI does not affect it, but Pehkui does, so yes tinies do receive increased fall damage, but it is not ASI doing it.
There are some exceptions, the following sources of damage are not increased:
Starving in hunger
Drowning in water
Damage from falling into the void or world border
Damage from wither effect
Damage from /kill
Entity cramming
Being stuck in a wall
Dragon breath
Damage from touching cacti¹
Damage from standing on magma blocks²
Damage from flying into walls very fast with elytra
Damage from sweet berry bushes¹
1: These kinds of prickly damage sources maybe should do more damage to tinies, because well, thorns would be like swords to them. However, I also feel that tinies would not have much problem not being impaled by these things, in the same way bugs can climb cacti just fine. Then, tinies below 0.25x scale straight up don't take this damage anymore.
2: Magma blocks SHOULD deal increased damage to tinies, and crouching should not help you, but this would be unecessarily annoying really so let's just leave it at normal damage. Maybe in a future update magma blocks will be adjusted, because I like the idea that tinies really need normal players to be carried over magma blocks that are otherwise impassable xP
The smaller you are the more damage you take, up to 25x by default. Beware, because the multiplier increases quickly the smaller you are under 0.5x scale.
The damage multiplier is the same number as the damage buff dealt by beegs, which can be configured per the instructions in that page.