What happens if both creatures in combat have first strike?

They both deal damage in the first-strike combat damage step simultaneously, so it resolves just like a normal combat between two creatures without first strike.

Can first strike protect a creature from Deathtouch?

Yes, if the first striker can kill the Deathtouch creature in the first-strike step; the destroyed creature never reaches the normal damage step to deal its Deathtouch damage.

What is the best First strike card?

By popularity, First strike is among the most-played First strike cards — see the full ranked list above.

Best First strike cards in MTG

First strike: A creature with first strike deals its combat damage before creatures without first strike deal theirs.

First strike lets your creatures kill smaller blockers or attackers before taking damage back, making it superb on defensive walls and combat-focused creatures. It effectively negates Deathtouch on creatures that do not also have first strike, since your creature can destroy them before they deal damage. Pump effects that boost power are amplified because the extra damage lands first.

FAQ

What happens if both creatures in combat have first strike?: They both deal damage in the first-strike combat damage step simultaneously, so it resolves just like a normal combat between two creatures without first strike.
Can first strike protect a creature from Deathtouch?: Yes, if the first striker can kill the Deathtouch creature in the first-strike step; the destroyed creature never reaches the normal damage step to deal its Deathtouch damage.
What is the best First strike card?: By popularity, First strike is among the most-played First strike cards — see the full ranked list above.