My Solution:
The game state stays unchanged - no rewinding. The Active player receives a Caution downgraded from a warning for committing a Tournament Error - Communication Policy Violation.
Reasons for my decision:
The active player wanted to “assign” damage while casting the spell. However announcing how much damage a spell does upon resolution is not part of the “casting a spell” steps. That would only be the case, if damage were to be devided among targets.
Tribal Flame has only one target. Upon resolution of that spell, it is checked how much damage tribal flame deals. This information is derived from a zone that is free information for every player. Blood crypt has 2 basic land types - swamp and mountain. The nonactive player destroyed Blood Crypt before Tribal Flames resolved. To make the decision whether to activate Tectonic Edges the nonactive player had to anounce a Target. By doing so he had to check the lands that are valid targets for tectonic edge and also had to check if the ability could be activated (only if an opponent controls 4 or more lands).
By doing so, the nonactive player (if not sooner) should have been aware of the situaton that the active player controlled only 4 basic land types.
The IPG would allow me to rewind the game to a state prior to the error. But where was this “error”. Annoncing a wrong amount of damage even though that is not required while casting a spell? This could be a Tournament Error - Communication Policy Violation. It is one of the standard cases of this infraction because a player represented wrong derived or free information.
Or the tactical error the nonactive player made? The IPG is not there to undo tactical errors commited by a player but this is what would happen if the game was rewound. The nonactive player would get a second chance to think about his “Tectonic Edge-Move”. So rewinding the game in this situaton would give the nonactive player an advantage to correct his tactical error.
Since the infraction commited by the active player was unintentional the queston that remains is if he should get a warning or a Caution. Since the situation is clear to both players and dealing with it takes far less time than reading this post - I would tell the active player not to announce any amount of damage while casting spells like tribal flame but to wait for the spell to resolve to then determine the damage. I would explain the nonactive player that rewinding the game would allow him to undo his tactical error of activating the Tectonic Edge.
Edited Denis Leber (June 26, 2015 03:00:58 PM)