The presence of luck-based mechanics in a strategy game can be both a blessing and a massive frustration.

In the context of lane-pushing arena battlers, RNG is typically minimized compared to card games or auto-battlers.
Starting Hands and Card Rotation
Your starting hand is entirely random, which can immediately put you at a massive disadvantage against an aggressive opening.

Professional players build their decks specifically to minimize the chances of a truly unplayable starting hand.
Never run a deck that is too heavy.Try to fix your rotation safely.Move on to the next match quickly. The Unpredictable AI
Sometimes a unit will retarget unexpectedly due to a micro-movement by another troop, completely ruining your defensive setup.

Leaving a slight margin for error in your defensive placements is the best way to handle AI unpredictability.
Battler CategoryRNG DependencyAuto-ChessSkill comes from long-term statistical managementStandard Tower RushVery Low - Only the starting hand is randomized Accepting Randomness
Getting angry at a bad starting hand only causes you to make further mistakes and lose the match entirely.

Focus on improving your timing and placement, and let the RNG sort itself out in the long run.