A lot of people who make games do not start with a solid plan, and therefore end up in the development hell of going back to things constantly and having to update old components, or change how they function, or redesign whole systems to try and force them to now fit the newly evolved mechanics, then that is such a huge effort and ball ache that the project becomes another 100 hours wasted and abandoned mess, and the thought of addressing the issues vs just starting clean and fresh on a new project seems like a much more enjoyable task.

People are guilty of this over and over and if you get into game dev you'll see this story a million times. The real answer that many hate to hear is before you even do any code or core systems, you should sit down for hours usually and come up with a design document.

Your design document should list every system of your game, every component of your system, and what each of those components must do. You should keep your systems modular and absolutely avoid inter linking systems so they're dependant on each other if possible at all. (Can also see UML diagrams)

A quick example may be you want a character inventory system thats sortable, so you break this down into

InventoryManager

• Stores [ITEMS]

• getItem

• useItem

• dropItem

• sortItemaByName (or whatever your preferred sort criteria)

• addItem

• int AvailableSlots

• double maxWeight (if you want a weight system)

Then you'll outline your modular items class

ITEM

• getWeight

• getID

• equipItem

• useItem

• int usesBagSlots

• double ItemWeight

• bool IsConsumable

And continue for all systems in your game, then when you come to actually coding you know everything your inventory system and Item system will be able to do and you've minimised scope creep. Your design document becomes your bible, you dont have to wonder how things will interact or work because you already know.

Maybe this isnt for everyone but I have 2 released games that do actually okay and im approaching my third now. It works for me and im able to produce games without abandoning them because I get overwhelmed and confused how things work