Ruin Explorer
Legend
Agreed. ASI's are pretty integral to 5e encounter design, though not 100%. Just makes things more challenging when you hit 10% less often and deal 10% less damage, etc.
Yeah and I haven't analyzed it closely but my instinct is that the sum total reduction to capability will be more than the 10% looking at individual numbers in isolation would indicate.
Like, if you hit 10% less often and do 10% less damage that's more like 81% effectiveness than the 90% people might guess. Failing more saves, taking more damage as a percentage of total health, healing for less and possibly having less AC could really tank survivability too.