What your bank is worth

Interest pays in steps. Every 10 gold you hold at the end of a round earns one more, up to 5 at 50. Above the cap, every gold past 50 is free: hold 57 and 7 of it is doing nothing, so spend it on a few shops or some experience and the next round pays exactly the same interest. Below the cap, the gold between steps is not wasted. It is what reaches the next step a round sooner, so spend it only on something that wins rounds now, like a level that lands on an even step. Good players spend down to a step, not through it, and they do it every round they can use the gold.

Going through a step costs less than it looks. Dropping one step costs one gold of interest for each round you stay under it. If that gold buys the level or the upgrade that wins the round, the win pays 1 back by itself and keeps the streak gold coming, the way Streaks are a choice shows. A bank is worth the gold it makes, and a board that wins makes more than a bank that loses.

Interest also only pays while you are alive, so a bank is worth its interest times the rounds you have left. Early, that is a lot of rounds, and losses are cheap: a stage 2 loss with three enemy units standing costs 5, a stage 4 one 11. Saving early has time to pay back. Late, it is a handful. At 30 health in stage 5 the same loss costs 13, and you have 3 left. Holding 50 gold there pays 5 a round for those few rounds, while the same 50 gold is 25 shops today.

That is the point where health, not gold, is what you are short of. When the rounds you have left are few, every gold should be on the board that has to stop the losses: roll it, level with it, and go out with nothing, or better, do not go out. The game review flags the other ending: getting knocked out with 24 gold or more, where nine in ten players who finish in the bottom four go out with less.

It works the other way too. With plenty of health and a plan that needs gold later, health is the cheap resource: let fights you cannot win go, keep the bank growing, and spend the health instead.