Knights of the Round
While attacking with token creatures produced by Urabrask's Forge, blocked by tokens generated from Knights of the Round, and City On Fire on the battlefield, excess damage not applied to Player.
-
Rezzahan#77802
commented
Combat damage assignment does not take into account replacement effects and prevention effects that will alter the actual damage dealt. You can only assign the normal combat damage of the attacker. AFTERWARDS the assigned damage will be trippled by City on Fire when the damage is actually dealt.
In a similar vein, if a prevention effect will prevent 1 damage to a blocker for example, you can still trample over with the normal damage, the blocker will then just not die because it receives 1 less damage.