Final answer:
Pirates at Tier 1 in certain video games provide several benefits to Mercenary units, including bonus attack damage, increased movement speed, and the ability to recruit additional members during battle.
Step-by-step explanation:
The effect of having Pirates at Tier 1 in certain video games (such as Teamfight Tactics) is that Mercenary units gain bonus attack damage, have a 50% chance to drop 1 gold when they kill an enemy, gain increased movement speed, and can recruit additional members during battle.