How Does Tolarian Library Interact With Mulligan Rules?

I’m more of a casual kitchen-table player, but whenever I slip "Tolarian Library" into a deck it feels like I’ve been given a tiny library-lab to tinker with during mulligans. The straightforward way to think about it: a mulligan’s big draw of seven is still drawing cards, so the Library’s “if you would draw a card, instead…” text replaces those draws. In practice that means you get to apply its top-three-look-and-keep effect for each card you draw while assembling your opening hand. So drawing seven with it in play is like repeating the Library’s effect up to seven times as you take that hand.

A couple of useful tips from my games: do the replaced draws one at a time and deliberately order how you replace draws to leave good cards on top for later picks. Also remember that after you draw your mulligan hand you still may need to put cards back to obey the London mulligan rule (put N cards on the bottom), and those put-backs are separate from draws and won’t be affected by the Library. If you’re used to old-style mulligans (draw one less each time), the concept is similar but the mechanics differ; with the modern mulligan you can sculpt more because you always redraw seven then bottom. I love how it rewards careful sequencing—feels like chess with cards.

I still remember the first time I played with "Tolarian Library"—it felt like cheating in the best way. Practically speaking, its text is a replacement effect that changes how you draw cards, and that means it applies to mulligans just like it applies to taking your normal draws. Under the current London-style mulligan you draw a full seven-card hand when you decide to mulligan; each card you draw is subject to replacement effects, so "Tolarian Library" gets to replace those individual draw events. In real terms, that means when you draw your seven cards you will, for each draw, look at the top three cards and choose one to put into your hand, putting the others back on top in whatever order you like. That gives a ridiculous amount of control over sculpting your opening hand.

There are a few practical wrinkles I always keep in mind: replacement effects are applied one draw at a time and in a chosen sequence, so you can optimize what you leave on top for subsequent "Tolarian Library" uses. If any other replacement effects would also apply to a draw, you have to choose the order those replacements are applied (you or your opponent choose when appropriate), which can get fiddly in corner cases. Also, after you finish drawing your starting hand and put cards back for taking a mulligan, the act of putting cards back isn’t a draw and so isn’t affected by "Tolarian Library." I learned this the hard way in a team event—library manipulation during the mulled draws can set up insane opening turns, but you still have to be careful about the order you perform your replacements and which cards you bottom for the mulligan step. It’s powerful, but the timing and replacement-order choices are what make it elegant, not broken.

Short version from my experience: "Tolarian Library" replaces draws, so it works during mulligans. With the London mulligan you redraw seven cards when you mulligan, and each of those draw events is replaced by the Library’s effect—meaning you look at the top three and pick one for each draw as you build your opening hand. That lets you sculpt the hand far more than a raw seven-card draw would.

A few practical notes I’ve learned: replacement effects are handled one draw at a time, so you can order the replacements to set up future picks; if there are other draw-replacement effects present you’ll need to decide their order of application. Also, putting cards back for the mulligan (the part where you bottom N cards) is not a draw and isn’t affected by the Library. It’s a subtle interaction, but once you’ve done it a few times it becomes very intuitive and powerful.