Dev diary: why the Boss Run never refills your shields

One pool of shields, on purpose

The rule everybody notices first: your shields don't come back between bosses. The game counts your pool once, when the run starts, from the same things as always (your player level, the DEF on your gear, your gems), and that pool walks with you from the first boss to the last.

We could have topped you up after every kill. We tried to imagine that run and it was boring before we even built it. If every boss starts with a full bar, every boss is a separate fight, and the run is just the campaign with fewer menus. The thing we wanted was the feeling of the fourth boss remembering the mistake you made on the second one.

So a shield lost early is a debt you carry. That's the whole design in one sentence.

Healing still works, by the way. A class skill that patches your shields does it in the run exactly as it does in a normal round. It just can't push you above the pool you started with. You can mend the armour, not buy a bigger suit halfway through the dungeon.

No revive, because a ranking should mean something

In the campaign, a lost round can be saved with a revive. In the Boss Run there is none: the last shield breaks, the run ends, and you get a quiet card with your depth on it.

This one wasn't a hard argument. The Boss Run has its own ranking, Today and All time, and a ranking you can buy your way up is a receipt, not a ranking. The same thinking sits behind the daily ceiling on runs: there's a hard cap per server day, and runs you pay for count toward it too. We wanted the board to measure how strong your build is, not how stubborn your wallet is.

The board itself is simple. Today ranks by how deep you got first, and by your fight time second. All time ranks your best depth, then how many times you've beaten the whole line-up, then how many bosses you've ever slain.

Tip: The clock stops on the card between bosses, and the next fight starts only when you press the button. Take a breath, check your shields, stretch your thumb. It costs you nothing on the board.

The day the first bosses were a formality

Our first version used each boss's campaign numbers and nothing else. It felt fair on paper. Then we played it.

The early bosses are tuned for one round with a full set of shields and a player who has just met them. Meet them again with an endgame build and they fold like a camping chair. In testing, the opening tiles of the run played out so alike that nobody could tell them apart afterwards. A whole opening, one blur, zero tension.

So now the run has a floor. A boss's HP and the strength of its strike in the Boss Run can't drop below a minimum, and that minimum climbs with every place in the line-up. A boss whose campaign numbers are already higher keeps them: we never made a late boss weaker to fit a curve. The result is a run that starts as a warm-up and ends as a wall, which is roughly the shape we drew on the whiteboard in the first place.

The phase shells from 1.2.2 follow every boss into the run as well. So yes, the fire shell that takes your last shield right before the finish is in here too. We're sorry. Mostly.

Loot you keep, even when you fall

A run that can end on any boss needs one promise to feel fair: what you won, you keep. Every kill is reported to our server the moment the boss goes down, the loot is rolled there and written to your account right away. Fall on the very next boss, close the app, drop your phone in the bath: the loot from that kill is already yours.

Two more decisions sit next to that one:

• Gear is the main prize. A boss in the Boss Run is more likely to drop its Rare and Epic gear than the same boss in the campaign. Coins come in full. Experience is cut on purpose, because a run that knocks over every boss in one sitting would otherwise push you up player levels faster than the rest of the game can keep up with.
• Loot drops on every run. Here's where we changed our minds. The first plan gave loot only to your first run of the day, and any extra run counted for the ranking alone. In practice, a boosted run without loot read like a punishment for wanting to play more. Runs are already capped per day, so we let every one of them pay.

And boss cores, the material every Legendary needs in the forge, only drop here. The deeper the boss sits in the line-up, the better its chance to drop one. That's the other reason the run is worth playing on the days you don't beat your record.

A roach opens the show

A small story we like. There's one boss the campaign never lets you fight: Tonatos, a forest roach whose campaign slot went to the tutorial. He was all dressed up with nowhere to go. The Boss Run gave him a job. He opens the line-up every single day, and it's the only place in the game where he lives.

The rest of the line-up isn't written by hand at all. It's built from the campaign's own boss rounds, in campaign order, each boss with its own numbers. When a new biome brings new bosses, they join the run without anyone touching the mode. Less work for us, and no chance of somebody forgetting to add the new scary thing.

What we hope you feel

We wanted the best ten minutes of your day to be a little bit tense. You check your gear before the start (the game warns you if something won't survive the whole run, because every kill wears it down a little), you play the opening carefully, and by the last bosses you're counting shields the way you count the coins for a chest you swore you'd save.

When you fall, we hope you know why. Not enough DEF, a spell fired a boss too late, a gem slot left empty. All of it is fixable before tomorrow's run, and the Boss Run guide has the habits that help. The full line-up, with each boss's numbers, is on the Boss Run page.

See you on the board. We'll be the ones losing to the fire shell again.