Commander Bot?
We had a stretch where only 3 players were available for a few weeks in our playgroup and we started discussing a bot to fill out the 4th seat. This is my attempt at writing down rules for how a bot would play. It's not meant to be competitive or even win, but I still want it to have some spicy plays.
I based the format of this Play around Capricopian where any player can activate the ability. When I searched (https://gatherer.wizards.com/Pages/Search/Default.aspx?action=advanced&text=+[may]+[activate]+[this]+[ability]) for this I found more support than I expected. So the main idea is to allow the players to use the bots creatures to pump or negate their powers and abilities.
Our main concern was how the bot would choose targets, such as for removal, attacking and blocking. The real difficultly stems in determining when the bot shouldn't just ram a 1/1 into a 6/6 and keep it back as a blocker. And also so that the bot doesn't just choose the player with zero blockers. The other concerns were whether the bot would play off the top of their deck, have a mana base and how card draw, discard and other mechanics worked.
I chose to ignore lands to start with, to keep it simple. This also means the bot doesn't ramp, and has a different deck size. I want to nail down how to choose attackers, when to hold back, and how to block. If the bot can do that fairly enough I'll try another bot with lands.
I wanted the bot to have good board interaction and not be boring so using cards with abilities anyone can activate is a great way to keep the players engaged on the bots turn. So even if the creature has a bad attack it's power can be adjusted or it's abilities neutralized by the players at the table. I supplemented these creatures with Myriad since they attack fairly as well.
As for top decking, I think adding Turn - CMC to power is a good balance formula to start with. If Progenitus came out on turn 1, it would lose most it's power. Conversly, if Glittering Lion comes out on turn 8 it gains some power so it's not a complete dud.
Choose Commander
O-Kagachi, Vengeful Kami
When attacking, attack player with highest life that attacked the bot on their turn and that can be dealt combat damage based on visible power and toughness of valid blockers. When the ability resolves, target creature with highest visible power with flying or reach otherwise Target permanent with highest Mana Value.
Yurlok of Scorch Thrash
Color Identity does not count for this as commander.
Yurlok will Attack any opponent that has no blockers.
Will not attack if
* 3 or more other creatures are also attacking.
* If it controls a permanent that has an ability that can be activated by any player that is not attacking.
It will activate it's ability without paying its cost during combat if any creature has an ability that can be activated by any player is attacking. And that ability can increase or decrease the power and or toughness of that creature.
It will activate it's ability when blocking if any blocking creature has an ability that can be activated by any player and that ability can increase or decrease it's power and or toughness.
Yurlock will always use the mana of it's ability to increase the power of creatures it owns that are in combat and in a manner that can trade favorably with a creature. It chooses to trade favorably with the highest mana value available, followed by power, then toughness. If there is any tie choose one at random.
If Yurlocks ability has not been activated by the end of the second main phase on the turn before the bot's turn, it will activate the ability at the end of that turn. The bot will burn the mana if available.
Choose Play Method
Untap
Bot gains +X Mana, where X is the Turn Number.
Bot does not lose unspent mana as turns and phases end.
Main Phase
Bot Has A Hand and Draws Cards
Starting Hand Size is 2, and draws 2 per turn. If it has 4 cards or more, the bot instead draws one card.
If the bot would mill a card, it would mill half that amount rounded down.
If the bot must discard a card, it chooses the card with the least power then least mana value.
Choose One
1. Play Highest CMC available that can be cast with available mana (Repeat until no more can be played)
1. Play the most cards that can be cast with available mana (Play lowest cost cards if more can be cast this way)
1. Alternate between the two (Odd rounds play 1, even rounds play 2)
1. Roll Odds or Evens
Plays the top card of it's library for free, once per turn.
The commander is instead cast if the cost to cast the commander is equal or less than the turn number.
Creatures have +X power where X is (Turn - CMC).
If X is in the Mana Cost, X is equal to the turn number.
If the bot would draw an extra card on it's turn, instead it plays the top card. This happens once on its own turn, otherwise nothing happens.
If the bot has treasure and it can use treasure to play the top card of it's library, it does so (it still gets one free card)
Choose Attack Type
The goes after higher life totals first. Put another way, the Bot can't attack the player with the lowest life if they have no blockers. This is only done as a last result if the bot can't get a positive result with any other attacks.
For each creature that can Attack,
- Bot can't attack the player with the lowest life without available blockers, unless another player is also being attacked or they are the last opponent.
- The player with highest life without visible blockers
- The player with highest life without a creature that can visibly defeat it (Such as having power greater than it's toughness, having deathtouch, or if it assigns damage that would otherwise defeat like using toughness or double strike)
- The player with highest life that it can trade creatures with
- The player with the highest life if it can attack with more creatures than blockers are available for
- If the bot can't attack into a player and either trade or damage the opponent, it may attack the player with the lowest life even if they have no blockers.
- If the bot can't damage any player, defeat or trade with a blocker, then it holds the creature as a blocker.
Creatures have a Myriad like ability. Each creature the bot plays has a copy with a Vendetta for each opponent. These copies do not Enter or Leave the battlefield and does not trigger any abilities. Each player needs to destroy or exile their own copy. The original can not attack or block and the copies can only attack or block the player it has a vendetta against. When all copies have left the battlefield, the original is removed in the same manner. If a player would gain control of their copy, they instead gain control of the original and all copies. And the copy with a vendetta against that player is removed from the battlefield.
If a creature has Myriad, it loses that ability and gains Vendetta.
Blocking
When a player attacks the bot, opponents of that player may decide optimal blocking if they are in agreement.
For each creature attacking the bot, starting with the largest visible power
1. The bot will block with the creature with the least amount of power required to visibly defeat the other creature
1. The bot will block with the creature with the least amount of toughness required to survive the visible power of the other creature.
1. The bot will block with the creature with the least toughness
1. The bot will block with the creature with the least power
Visibly means the power and toughness it can see when blockers are declared. This does take into account double strike, and if combat damage is assigned by means other than power. It does not take into account activated abilities that may be used to pump stats.
Targeting & Specific Card Rules
When targeting always choose an opponent if available, choose the player with the highest life with a valid target, and if that target is a creature, target the highest visible power, otherwise target the highest Mana Value. If targeting Self, instead replace highest with lowest. Only target if the ability can visibly resolve (doesn't try to destroy a target if it's indestructible when another valid target is available)
O-Kagachi, Vengeful Kami
When attacking, attack player with highest life that attacked that can be dealt combat damage based on visible power and toughness of blockers.
When ability resolves, target creature with highest visible power with flying or reach. Target highest Mana Value otherwise.
Deadly Designs Target the Creature with the highest power output of the player with the most life, then target the Creature with the highest mana value of the player that can visibly produce the most mana.
Hammers of Moradin Target the creature with the highest visible power that is untapped and able to block.
Scion of Calamity Target the highest mana value available.
Firbolg Flutist Target the creature with the highest visible power that can be produced (such as through double strike, or double damage)
Abilities Any Player May Activate
Some cards have abilities that any player can activate such as Flailing Ogre. These abilities can both give and take. Other cards do not like Glittering Lion.
Optional: Counter Activated abilities of permanents owned by the bot.
At the beginning of the game, determine if creatures with abilities that can be activated by any player owned by the bot gains the following ability. Counter it's own ability on the stack by paying X where X is the amount of mana spent to activate it. All other conditions of the ability must also be met.
In the case of Capricopian the ability and counter ability can only be activated by the player it is attacking.
Summary
At the beginning of the game, the following should be decided before play begins.
- Choose a Commander
- Choose Play Method
- Choose Attack Method
- Choose Optional Rules
Example:
- Child of Alara
- Bot (Alternate)
- Vendetta
- Counter Abilities
