The Battlefield
VerifiedFeb 26, 2026
Clock of Omens + Mr. House, President and CEO + Vexing Puzzlebox
Overview
Clock of Omens can tap two untapped artifacts you control as its activation cost to untap a target artifact, allowing additional activations of Mr. House, President and CEO or Vexing Puzzlebox beyond their single-tap state. Vexing Puzzlebox's 
ability is a mana ability that resolves immediately and causes an immediate d20 roll (Ruling [2022-06-10]). Any die rolls (whether from Mr. House resolving or from Puzzlebox's mana ability) will cause Vexing Puzzlebox's triggered ability and Mr. House's “Whenever you roll…” triggered ability to trigger as appropriate; the die roll(s) themselves have no inherent effect beyond causing those triggers (Ruling [2024-03-08]). Activating Mr. House requires tapping it (), which is subject to the tap/activation restrictions in .
ability is a mana ability that resolves immediately and causes an immediate d20 roll (Ruling [2022-06-10]). Any die rolls (whether from Mr. House resolving or from Puzzlebox's mana ability) will cause Vexing Puzzlebox's triggered ability and Mr. House's “Whenever you roll…” triggered ability to trigger as appropriate; the die roll(s) themselves have no inherent effect beyond causing those triggers (Ruling [2024-03-08]). Activating Mr. House requires tapping it (), which is subject to the tap/activation restrictions in .Step 1
Activate Vexing Puzzlebox’s mana ability: you tap Puzzlebox, immediately add one mana of any color, and immediately roll a d20; because this is a mana ability it doesn’t use the stack (Ruling [2022-06-10]).
mana ability: you tap Puzzlebox, immediately add one mana of any color, and immediately roll a d20; because this is a mana ability it doesn’t use the stack (Ruling [2022-06-10]).Step 2
That d20 roll creates triggered abilities: Vexing Puzzlebox’s triggered ability (“Whenever you roll one or more dice…” ) and Mr. House’s triggered ability (“Whenever you roll a 4 or higher…”) will trigger if their conditions are met; those triggers are placed on the stack and will resolve later (Ruling [2024-03-08]).
Step 3
To use Clock of Omens to allow another tap activation, activate Clock’s ability by tapping two untapped artifacts you control as its activation cost (those artifacts become tapped when paying the cost) and choose an artifact to untap when Clock’s ability resolves — for example, target Mr. House to untap him so you can pay his cost again. The tapping to pay Clock’s cost happens as part of that activation, and the untap effect happens when the ability resolves.
cost again. The tapping to pay Clock’s cost happens as part of that activation, and the untap effect happens when the ability resolves.Step 4
Activate Mr. House’s 
, ability by paying and tapping Mr. House (subject to ); that activation goes on the stack. When it resolves you roll the indicated d6/d6+... dice, and those rolls produce triggers for abilities that care about dice (including Puzzlebox’s triggered ability). The rolls themselves have no inherent additional effects (Ruling [2024-03-08]).
, ability by paying and tapping Mr. House (subject to ); that activation goes on the stack. When it resolves you roll the indicated d6/d6+... dice, and those rolls produce triggers for abilities that care about dice (including Puzzlebox’s triggered ability). The rolls themselves have no inherent additional effects (Ruling [2024-03-08]).Step 5
Repeat as resources and available untapped artifacts allow. Each extra activation still requires meeting costs (tapping artifacts for Clock, paying Mr. House’s , and having untapped artifacts to pay Clock’s activation cost).
, and having untapped artifacts to pay Clock’s activation cost).Resolution
You can use Clock of Omens to untap Mr. House or Vexing Puzzlebox so you can activate their tap abilities more than once, but each use still requires paying any other costs (for Mr. House, paying and meeting the tap-symbol activation rule in ). Vexing Puzzlebox’s is a mana ability and does not use the stack (Ruling [2022-06-10]); its roll happens immediately when that ability is activated and will produce triggers (including Mr. House’s triggers). Die rolls caused by Mr. House’s activated ability will also generate triggers that care about rolls, but the rolls themselves don’t do anything except create those triggers (Ruling [2024-03-08]). There is no inherent infinite loop just from these three cards by themselves — you are limited by available untapped artifacts to pay Clock’s activation cost and by paying Mr. House’s other costs.
and meeting the tap-symbol activation rule in ). Vexing Puzzlebox’s is a mana ability and does not use the stack (Ruling [2022-06-10]); its roll happens immediately when that ability is activated and will produce triggers (including Mr. House’s triggers). Die rolls caused by Mr. House’s activated ability will also generate triggers that care about rolls, but the rolls themselves don’t do anything except create those triggers (Ruling [2024-03-08]). There is no inherent infinite loop just from these three cards by themselves — you are limited by available untapped artifacts to pay Clock’s activation cost and by paying Mr. House’s other costs.Feedback