I find alternate rounds to be the most interesting when they open up territory for deck building. Dibs doesn't really do that, or if it does, I don't find it's method that interesting. There are already plenty of standard 3CM decks that rely on being dominant on the play and just hope that the meta is slow. Dibs would basically just limit your deck options.
In general, improving mana options does a lot to change the format. Almost every format like that has been dynamically different than Vanilla, which I think should be the main goal.
Changing game rules varies wildly on how a big an impact is created. I tend to think they don't do good enough a job.
Looking at the current options:
3 New Design Paradigm: Creatures cost
less to cast. Noncreature spells cost more to cast.The restriction on noncreature spells is a way to force people into utilizing the creature cost discount. It's very "format-crafting", but I like it enough. It's too easy to avoid round rules too often.
4 Endless Ones: At the beginning of your upkeep, you may exchange any card in your hand with an Endless One from outside the game.
This just doesn't do anything useful. It influences you to play charge lands, but otherwise, it's not an interesting idea at all.
Memento: Players start with a Memento artifact card in hand. It costs
and has Squee, Goblin Nabob's ability.This offers a lot of subtle deck-building decisions. It's a neat way to emphasize that you don't have to give players a lot for real format changes to occur. It might actually be a moot point, though; I can see this format being the victim of "I played BridgeTongs/Titan/LeylineKarakas, your cute Memento deck does nothing." But that happens sometimes.
Berserker: Creatures can't block. Combat damage can't be prevented. Prevent all non-combat damage that would be dealt to players.
Seems pointless. If your deck would block, chances are you're just gonna win attacking anyway. It doesn't actually change much to the way you'd build a 3CM deck, which is a sure sign that it's not much of an alternate format.
Spirit Guides: Each card has "Exile this from your hand: Add
or one mana of any of this card's colors to your mana pool."There's very little chance that this has merit. Even if there's a deck that can utilize this, it's one deck out of many, and most 3CM Vanilla decks are gonna come to the program as is. In fact, the decks that generally gain the most from this are those that already use Spirit Guides.
