I just wanted to get some insight on this question I was thinking about, as I fear it may be too hard to answer. Yet we know similar mechanics for games like Pokemon, so it is not technically impossible for someone to have dug into the game code that far.
Does The Binding of Isaac cheat against/for the player?
When playing The Binding of Isaac, I always had the impression that the game in a way "cheats" against the player. Often, a run feels like the items you are given (outside of those forced by the player using mechanics like Death Certificate, rerolling, Spindown Dice, etc.) are chosen in a way to actively hinder the player.
Some examples out of my mind:
- items that are mostly avoided (Broken Mirror, Cursed Eye, etc.) tend to spawn on Curse of the Unknown floors (so that you can't see them before picking them up)
- mobs often seem to be chosen as hard counters to the items you were given: Ludovico Technique? Expect spider hell and everything else that moves erratically and very fast. Items that give you creep/floor damage? Everyone flies, including bosses.
- two items "you win" combo that include base, no angel/devil items almost never appears (for example I never managed to get Daddy Long Leg and Gnarled Leaf in the same run outside using Death Certificate)
Obviously, most of the time I just consider these examples as negative reinforcement: just remembering the cursed runs and forgetting the good ones. And since the frequency of cursed runs has been increasing with every DLC (with new, poorly designed mobs added every time), this seems quite reasonable.
That said, considering how imbalanced the game is (see: Unstable Equilibrium on TVTropes), I have started to ask myself if there is anything true in this. Some example of unfair mechanics include:
- mobs that can teleport often teleport INSIDE the player with unavoidable damage.
- things like Mom Feet hit you even as you are running around (no delay between the shadow and the stomp)
- unavoidable damage rooms (either for the current character or for any possible character - see the 4 Cage room spawning on the room door)
- glitched items (including those from Corrupted Save, MissingNo and the April Fool challenge) can still trigger instant death effect like Plan C and Suicide King. This is taken to extreme when the effect is not tied to a player command (for example, Suicide King being triggered at the start of a floor). In some cases a glitch item can even crash the game.
- mobs that seems to be programmed to seek unavoidable damage situations: for example The Adversary shoots an homing brimstone laser that is usually countered by standing behind them. Only issue being the fact that they have a weird tendency to get in a corner of the room...
- Delirium: this boss is know to constantly using telefrag against the player.
- multiple boss and even normal mobs having attacks that simply can not be avoided if the player has a lower speed stat.
At the same time, some mobs seem to be programmed to avoid unavoidable damage in an attempt to be more fair. Coincidentally these are mostly the older ones.
- Larry Jr seems to be coded to avoid trapping the player in a non escape spot, and will often turn back at the last second in such cases
- despite being based on Bomberman, Wrath seems to have the same logic as Larry, trying to avoid trapping the player between a wall and a bomb.
- Hush homing laser speed apparently is scaled to be relative to the players speed so that you should always be able to outrun it.
The question is therefore simple: Does any proof exist that the game contains logic that is actually skewing the gameplay against or for the player? Or is my mind just playing tricks on me?