system
Given the following post, respond as if you're commenting on Reddit:
human
[Mighty Morphin' Power Rangers] Is there a reason Rita Repulsa didn't make her monsters giants as soon as they were on Earth?

Bonus Question: Is there a reason the Power Rangers don't immediately bust out their super combo weapons, zords, or even Megazord?
gpt
She's not trying to cause mindless destruction. If she wanted to stomp the city flat, she could manage it pretty easily by sending down Goldar with a few other giant monsters. Each of the monsters she sends down, she sends down for a specific reason. It's only until the Rangers screw up her plans that she bulks them up.

As for why they don't bust out super weapons and such immediately: They have to follow escalation of force. Zordon made them promise to never escalate a fight. If they violated that, he'd strip them of their powers. The Rangers are ultimately a defensive team, after all.

So, it's only after they fight the monsters and establish that, yes, this one can't be taken down with fists, that they break out normal weapons. Once that fails to kill them, they combine their weapons. Once the monster goes giant, they to the Megazord.

In every occasion, they match the force they believe the monster is putting out. Once they establish that he's stronger than that, only then are they allowed to break out heavier weaponry.

That said, they can skip steps if they feel that a stronger response is instantly needed. For example, they usually don't engage the monster with their Zords because they know that their individual Zords usually won't do the job. In one occasion, a child was directly threatened by a monster, causing them to leap straight to the Megazord to save the kid from the (still human-sized) monster.