I recently had an issue where I executed the engine I built around Trumpeting Carnosaur and Flickering Hound in a game but the stack became very large and ultimately, the Arena client punished me for it and I lost the game. In this scenario, I knew the timer would be an issue so I was clicking through the interactions as quickly as I could and had no time to calculate. My opponent was significantly ahead on life, so it was unclear when was 'enough'. Additionally, late Delney discoveries significantly increased the time to execute on the stack already played. I ran out of time while moving as quickly as I could and my own Terror of The Peaks effects defaulted to targeting me and nearly killed me. I've had similar issues with combo decks in the past.

In this scenario, it was an instant win over the board but a loss on Arena, wherein, I was punished for executing my strategy. I propose there are several changes Wizards could make to improve how large stack resolutions are handled for both players.

Firstly, I'd suggest an increment based timer, as is frequently used in speed chess. The player gets a little time added back onto the wick when they take a meaningful action, rewarding active play and keeping things moving. This should have an upper limit (total amount of additional time that can be allocated) still to prevent Players stalling out the game with infinite combos.

When Players do still run out of time, with the increment timer active:
- Where the max limit has been reached with the increments (active play), they should be unable to add any further actions onto the stack without interaction from their opponent. Any remaining interactions on the stack should be automatically handled as with the current system (with some logical improvements).
- When the stack is still being executed by arena autonomously after the time has expired:
- Damage dealing effects should default to targeting the opponents face first, then permanents they own, then no target, and only when none of those options are viable, the casting player.
- When time expires with cards on the stack during active play (increment used) the client should end the phase of play, rather than the players turn. If time expires through inactive play (increments not expired eg. stalling) the turn should be skipped as normal.
- Allowing players to batch interactions of a specific kind of interaction (e.g. Target Opponent for all Terror of The Peaks damage)) when the stack reaches a certain threshold could further save time.
- Additionally, disabling animations once the stack reaches a certain threshold would improve performance and speed up execution time

My argument is that the current timer creates a counterproductive incentive: players executing complex combinations are encouraged to rush through interactions rather than assess the board state and determine when they have achieved lethal. This can result in unnecessarily extending combinations, which further increases the time needed to resolve them. I think these changes would better reward skilled play, help players to more swiftly navigate complex interactions on the stack, and ultimately improve the gameplay experience for both players.