{Hidden strings}

[Rontron]

Does {Hidden strings} cipher effect work if its ciphered on to say {Niv-Mizzet, Dracogenius} and you use his ability to do one damage to target player will the ciphered spell resolve?

[InfinitiveDivinity]

Niv would have to attack and deal combat damage in order to cipher the strings again.

[addoexatrum]

Infinite is right, the answer is in the cipher wording. You only copy the coded card when combat damage is dealt not ability or effect damage.

[Rontron]

What about a similar combo with {hellrider} and {hidden strings} cipher will the spell cast for each time a creature attacks {hellrider} deals one damage?

[Crapshooter]

Combat damage, not ability damage

[Gorzo]

Cipher only triggers off combat damage.

Combat damage occurs when, in the combat damage phase, an attacking creature hits a defending player or blocking creature for damage equal to its power.

ALL other damage is considered non-combat damage. Even {Pit Fight} type fighting is non combat. Cipher will not trigger from this type of damage.