The April 2025 Mega Millions Redesign: A Math Walkthrough
Five game-rule changes, three downstream effects, and one paradox: better jackpot odds, worse expected value.
On April 8, 2025, Mega Millions launched its most dramatic redesign since 2017. Five rule changes, all at once. The headline change — improved jackpot odds — got most of the press. The cost change — $2 to $5 — is the one that matters mathematically.
The five changes
- Ticket price: $2 → $5
- Mega Ball pool: 1–25 → 1–24 (one ball removed)
- Jackpot odds: 1 in 302,575,350 → 1 in 290,472,336
- Minimum jackpot: $20M → $50M
- Megaplier: removed; every ticket now has a built-in random 2×–10× non-jackpot multiplier
Why the Mega Ball pool change
Removing a number from the Mega Ball pool (25 → 24) is the simplest way to nudge jackpot odds without changing the main pool. The arithmetic:
New: C(70,5) × 24 = 12,103,014 × 24 = 290,472,336
Improvement: (302,575,350 − 290,472,336) / 302,575,350
≈ 4.0% better jackpot odds
A 4% improvement is real but small. The communications around the redesign emphasized this number because it was the only direction the math moved in the player's favor.
The price-to-value ratio
Ticket price went up 150% ($2 → $5). Jackpot odds improved by 4%. Minimum jackpot went up 150% ($20M → $50M).
Comparing expected return per dollar spent:
New (at $50M min): EV ≈ −$4.70 per $5 ticket = −$0.94 per dollar
At minimum jackpot, the new fraction of your dollar that's expected loss is significantly higher than the old game. The minimum jackpot rose in absolute terms but not enough to compensate for the price increase given the constant overall odds.
The built-in multiplier: a real gain
Every $5 ticket has a random non-jackpot multiplier between 2× and 10×. Old games charged $1 extra for the Megaplier and capped at 5×. The new system bundles a stronger version into the base ticket. For non-jackpot prizes (most of a ticket's positive contribution to EV), this is a meaningful gain.
Estimated impact on EV: the multiplier raises non-jackpot prize expectation by roughly $0.30–$0.50 per ticket. So:
≈ −$4.27 per ticket
The paradox
The redesign improves the player's jackpot odds by 4% and improves the multiplier on small wins. Both are nominally pro-player changes. Yet the expected loss per dollar spent increased because the ticket price went up far more than the prize-side improvements compensate.
This is a well-known pattern in lottery game design: marketing emphasizes the improved odds (a number that goes down, which feels good), while the cost goes up by a much larger factor. Expected value moves against the player even as the headline number moves in their favor.