Help needed on weapon ability - make save or be knocked prone

[Myrdin Potter]

I think I am just over hungry right now and not seeing an example.

Sword of Giant Slaying has the ability if it hits a giant, strength save DC 15 or be knocked prone.

I don't need to test if a giant, I can just tell the player.

How do I code that ability?

[Myrdin Potter]

I can set a fixed cast ability for the save and then do another effect to make prone. Only choice the cast option seems to have is damage, not apply an effect. Is that right?

[LindseyFan]

I'd be interested in this answer as well, for a similar item.

[Trenloe]

Cast is always a 2 step process - roll the action (save, attack etc.) and then manually apply the resulting effect (condition, damage, etc.) if the action was a success (or failure in the case of a save). Just add a new effect action to the spell entry with the prone condition and click that if the save action failed.

[oukag]

I can set a fixed cast ability for the save and then do another effect to make prone. Only choice the cast option seems to have is damage, not apply an effect. Is that right?

Yes, this is correct. The "On Save" functionality is only used to determine if the damage should be halved on a save. If there is an effect with an ability, it needs to be manually added. Just like how damage needs to be manually rolled.