Hello,

I've made a chair and had all the EPs in SimPE checked. It works fine. However, I was curious if I should make a base-game compatible one, considering the existence of the "Pets" expansion. I put my chair in AnyGameStarter with the only thing checked (in AnyGameStarter) being "Base Game" and "Mansion and Garden" SP (couldn't get my AnyGameStarter game to run without it). And, the chair works fine! Despite there being no pets in this version of the game.

The chair was cloned from a base-game chair, but I'm still curious as to how this happened to be.

In a case such as this, is it necessary to make another/separate "base-game" compatible version for your object, even if it seems to work just fine with base game only?

Thanks in advance!
CT04.

There's difference between objects and compatibility.

The only thing chairs need for compatibility with pets is that if it's pets-compatible, pets can scratch/destroy it. You can use a BG-compatible chair in any game (sans scratching/petcompatibility). Most likely, the EP chair can be used in a non-EP game, or all that's needed is to re-flag it and it'll work.

Some objects have spesific EP requirements where there can be issues with compatibility. Items like fridges, book cases, stoves, and EP
spesific items. Some (if made spesifically as BG-only) just won't have the EP-spesific options. Others can crash the game. Some EP-compatible items can crash a BG/lower-EP game.

Cloning a basegame chair doesn't mean the item won't have EP functions, because in most cases the items were updated to add those. It's best to use BG items when you want to make BG-compatible items, though. If you really want a proper BG-compatible item, you'll have to untick all EPs in SimPE, and make sure it's flagged properly (in most cases with deco and simpler items that don't have EP-spesific menus, just changing the flag is fine)

An AGS with Base/M&G has the same EP requirements as all game packs. Using the UC AGS does not get you a way to test base game items only.

Whatever the latest EP checked in SimPE will determine what game version is required. In this case M&G, which is why the chair worked fine in your AGS. But it will not be compatible with anything less than M&G. This will also have all pet functionality.

Ah, so to make something truly accessible for everyone, SimPE has to be set to base-game only (and not just use a base-game chair)?

Mansion and Garden is a full update that includes functionality of previous EPs and objects of course will work in it. The oldest game you can comfortably run today is Open For Business. There is a medicine / kcarc for this EP. Testing in it will go a long way towards ensuring compatibility for your mod.

Some objects in later EPs were transitioned from having private interaction tables to semiglobal common ones for the class in OBJd. The interaction table format was changed in Pets with extensive pet motives, but older tables still work.

In your code, do not reference any functions from later EPs. You can recognize them having higher numbers and names that relate to witches and apartments. Quite often you can wrap them around a conditional test for whether the EP is present. If the new functions are skipped, it will work. Do not use any constants from new games. You can compare the literal values instead. There are fewer data fields in object data, globals and person data in earlier EPs.

Apartments can be detected with Set to Next - Controller - Apartment loaded (0xD4B48AA2 and/or 0xB4B33AB5), and Mansion can be detect if needed with Test Object Type for one of their windows (for example 0xF5C30B48, 0x95821D23). For the others you can use GameEdition flags. Note that Test Object Type will always return true in older games up to Pets and must be combined with other tests.