hello guys, we need to know if abilities like blast and burn on weapons mandatory or not?

i mean we know that abilities with surges must be activated but non surge abilities are mandatory or not?

if they are non mandatory must the attacking hero choose before the attack or after?

thanks in advance

Blast and Breath used to be mandatory, but were errata'd to be optional (see the FAQ).

In general, it depends on the ability text. Some abilities are written specifically to make certain things optional - Leap, for example. But most abilities are mandatory.

Antistone said:

+1

In addition, you do not have to spend surges. That makes most surge generated abilities optional.