From Dragon Quest Wiki

Thwack is an instant-death spell that targets a whole group of enemies, unlike Whack (which targets only one enemy).


Dragon Quest II

Thwack is learned by the Prince of Cannock at level 23, and costs 4MP to cast.

Dragon Quest III

Dragon Quest IV

Kiryl learns Thwack at level 24 and now costs 7MP to cast, remaining so until IX.

Dragon Quest V

Name Level
Snowbird --
Orc king 15
Samigina 20
Bianca 23
Nera 23
Debora 25

Dragon Quest VI

Thwack is learned by advancing to rank 7 of the Priest vocation.

Dragon Quest VII

Dragon Quest VIII

Angelo learns Thwack at level 22.

Dragon Quest IX

Thwack is learned by priests at level 34, and costs 10MP. It works off of the priest's Magical mending, raising the base accuracy from 50% once the stat hits 100 points, capping at 100% effectiveness (barring resistance) at 999.