Originally published on indiecore.net .

Part 1 of 10 on building a word-block puzzle engine. Series index at the bottom.

The second game was a copy of the first. That is not a confession, it is what everybody does,

and for about six weeks it is the correct decision — you do not know which parts are the game

and which parts are that game until you have built a second one.

The bill arrives later. I fixed a rounding bug in the star calculation, shipped it, and then

found the same bug sitting untouched in the sibling title, because the sibling was a folder

copy from before the fix existed. The fix took four minutes. Finding out the other game had it

took three weeks, because nothing told me.

What a copy actually costs

The honest number is not "duplicate code". It is the number of places a decision lives.

At the point I stopped, one game's src/ held 70 files : screens, the board renderer, the

store, hooks, the economy, the difficulty tiers, the sound layer, the ad wiring.…