Two-Headed Giant Variant

[Hanmac]

The main points:

• [ ] The Two-Headed Giant variant uses the shared team turns option.
• [ ] Each team has a shared life total, which starts at 30 life.
• [ ] Effects that cause players to get poison counters happen to each player individually. The poison counters are shared by the team.
• [ ] The Two-Headed Giant variant can also be played with equally sized teams of more than two players. For each player a team has beyond the second, that team’s starting life total is increased by 15 and the number of poison counters required for the team to lose is increased by five. (These variants are called Three-Headed Giant, Four-Headed Giant, and so on.)

[Jetz72]

Some notes/potential headaches about shared team turns:

Teams have priority, not individual players

There would probably need to be logic allowing players on a team to act in parallel. The simplest resolution here would be to ignore it and have an internal priority passed around within a team one at a time, but this may lead to inherently suboptimal play by the AI.

Giving this rule full support would likely involve different behaviors for a team of humans (who can communicate and act normally), a team of AI players (who need to decide amongst themselves which of their preferred next actions is best), and a team containing both human and AI players. Simplest resolution to that last scenario would be to let the human player make all decisions, but that kinda defeats the purpose of a team game to begin with. Perhaps human players could be provided with a view of the AI player's intent (like the AI suggestion tool in the dev menu), and then either take an action themselves or let the AI do what it wants to do.

Primary player

805.2. Within each team, the player seated in the rightmost seat from that team’s perspective is the primary player. If the players on a team can’t agree on a choice, such as which creatures attack or what order triggered abilities are put on the stack, the primary player makes that choice.

Should probably be the rightmost human player where applicable. This player could also play a role in deciding the order of actions. They should also be responsible for handling ordering of triggers on the stack, because:

Simultaneous triggers shared among teammates can be interwoven when placed on the stack

Per:

805.7. If multiple triggered abilities have triggered since the last time a team received priority, the members of the active team put all triggered abilities any of them controls on the stack in any order they choose, then the members of each nonactive team in turn order do the same.

I'm not sure if this is true for simultaneous zone transitions and other choices.

Extra turns, skipped turns, and turns controlled by another player are shared by the whole team.

Not a significant complication, I just wanted to remark that this rule causes severe balance issues and my play group always rule zeroes around it...

Combat.

Teams attack and block as a group. Your creatures can attack any number of players on the enemy team. Your creatures can block creatures attacking anyone on your team. "Attacking player" and "defending player" is determined separately for each attacker/blocker/defending player in accordance with a couple huge walls of text.

Getting the AI to consider how their teammates creatures will attack when making their own choices might be complicated. Could just leave all combat choices to the primary player for simplicity.