In SimAntics, the opcode of an instruction can either refer to a built-in command, known as a primitive, or to a subroutine. The subroutines can be privates (belong to the object) semiglobals or globals. A global will have an opcode 256 to 4095, a private will have an opcode from 4096 to 8191 and a semiglobal will have an opcode >= 8192.

Instructions are executed synchronously within the thread until something yields the thread, an error is fired or the stack becomes empty. An example of this is the Animate Sim primitive. In the behaviours found in the game, this primitive often has a loopback on the false branch which points back to itself. The primitive returns true if the animation is complete and false if it is not. The false then loops back to the Animate Sim primitive to run the next frame. If this code was executed synchronously no animations would ever be observed. Therefore some primitives yield the thread.

You can think of primitives as having the following return values. GOTO_TRUE, GOTO_FALSE, ERROR, GOTO_TRUE_YIELD, GOTO_FALSE_YIELD.

The documentation below for primitives and their operands is correct for The Sims Online. The Sims 1 and 2 operands may be slightly different.

Table of Contents

The Sims Online Primitives

0 - Sleep

Changes the current virtual thread's state to sleeping. The number of ticks to sleep for is determined by a stack variable (local) specified by the operand.

Offset: 0 1 2 3 4 5 6 7
Meaning: Stack Var # Unused

1 - Generic Sims Online Call

Main article: Generic Sims Online Call

This primitive is used to call upon game functions which are either not common enough to include as a primitive or very specialized with no parameters (eg. Disable/Enable Build/Buy).

Offset: 0 1 2 3 4 5 6 7
Meaning: Call ID Unknown (potentially any arguments?)

2 - Expression

Performs a logical or mathematical expression. The operator value describes what type of expression to perform and the other values determine the left and right hand side of the expression.

Offset: 0 1 2 3 4 5 6 7
Meaning: LhsData RhsData IsSigned Operator LhsOwner RhsOwner

The lhsdata, lhsowner, rhsdata and rhsowner are scopes as described here. Possible values for operator:

id name notes
0 >
1 <
2 == equality test
3 +=
4 -=
5 := assignment
6 *=
7 /=
8 IsFlagSet Checks the bit specified by the RHS in the LHS.
9 SetFlag Sets the bit specified by the RHS in the LHS.
10 ClearFlag Clears the bit specified by the RHS in the LHS.
11 ++ and < Increments LHS then returns true if LHS < RHS, false otherwise
12 %=
13 &=
14 >=
15 <=
16 !=
17 — and > Decrements LHS then returns true if LHS > RHS, false otherwise
18 Push* If LHS is either My List or Stack Object's List, push the value from the RHS onto the position specified by the data field.
19 Pop* If RHS is either My List or Stack Object's List, pop the value from the RHS list at the position specified and store it in the LHS.

*These only work if the operation is performed on a list!

3 - Report Metric

Used to record data. Not sure where this data goes…

4 - grab

Places the Stack Object in the Sim's (should be the thread's "Me" reference) slot 0.


No Operand.

5 - drop

Attempts to place the caller's held object (in slot 0) on an adjacent tile, starting in front.


No Operand.

6 - Change Suit/Accessory

7 - Refresh

Marks an object to be redrawn, update the light map of its room or update the room's room score.

Offset: 0 1 2 3 4 5 6 7
Meaning: TargetObj Unused RefreshType Unused


  • 0 - My
  • 1 - Stack Object's.


  • 0 - Graphic
  • 1 - Lighting Contribution
  • 2 - Room Score Contribution

8 - Random Number

Sets a variable referenced by a Scope to a random number between 0 and a specified value also referenced by a scope.

Offset: 0 1 2 3 4 5 6 7
Meaning: DestData DestOwner RangeData RangeScope

9 - burn

Spawns a fire object on the specified location if a fire object is not already there and the object on the space is not busy (or the allow busy objects flag is enabled).

Offset: 0 1 2 3 4 5 6 7
Meaning: Location Flags Unused

The location can either be 0: Stack Object, 1: in front of stack object or 2: floors under stack object (unused in TSO)
There is only one flag: 1: allow busy objects. If this is not enabled the fire will not spread onto objects that are not idle.

10 - Sims1.0 tutorial

This primitive isn't used in any of the behaviors found in The Sims Online.

11 - Get Distance To

Gets the Pythagorean distance between the stack object and the specified object in tiles, floored.

Offset: 0 1 2 3 4 5 6 7
Meaning: Temp # Unknown (Flags?) ObjectScope OScopeData Unknown

12 - Get Direction To

Gets the direction from the specified object to the stack object and stores it in the specified Scope.

The direction's basis or 0 value "North" is facing from where the house should be AWAY FROM the road. The following values 1-7 are a clockwise rotation around this direction in 45 degree steps, and each has a compass name as you would expect going clockwise corresponding with its direction. The directions of both of the objects are not considered for the calculation, just their positions.

Offset: 0 1 2 3 4 5 6 7
Meaning: ResultData ResultOwner Unknown (Flags?) ObjectScope OScopeData

13 - Push Interaction

Pushes an Interaction onto the Stack Object's tree queue.

Offset: 0 1 2 3 4 5 6 7
Meaning: Interaction # ObjectLocation Priority Flags IconLocation Unknown

ObjectLocation's meaning differs based on flags, see below. IconLocation is only regarded when a certain flag is set.


This would be better on the Interactions page, but it will remain here until we understand more about how they work.

id name notes
0 inherited priority Inherits the priority of this interaction.
1 maximum priority Instantly goes to the front of the interaction queue.
2 autonomous priority For interactions queued by autonomy.
3 user driven priority Higher than autonomous priority.
4 parent idle priority ???
5 parent exit priority ????what????
6 idle priority A sim's idle loop runs on this priority. When new interactions are queued, this one is suspended.
id name notes
1 Use icon from local Uses the icon from the object stored in the local specified by IconLocation.
2 Local Variable for ObjectID If set, the object the interaction is retrieved from is specified by the Local Variable pointed to by ObjectLocation. If not, it is specified by the Parameter pointed to by ObjectLocation.
3 continue as current Pushes the interaction as a continuation of the existing one. (before any following interactions that the user may have queued)
4 carry name over Uses this interaction's name for the new interaction instead of its true name.
5 Unknown
6 Unknown
7 Unknown
8 Unknown

There is functionality for "Interaction result type" and "Server Only (DEV ONLY!)" but I haven't been able to place these on the operand.

14 - Find Best Object for Function

Finds an object by function with the relevant Object Data or advertisement set highest, and with its entry point for that function not set to None. This is used for finding sinks, counters, ovens etc (in conjuncton with Get Distance To). If the object's "lockout count" is greater than 0, the object is ignored. This is used to iterate over all of the objects with the function, usually to find the one with the smallest distance. If the primitive finds an object, the stack object is set to it and the primitive returns true, however if the primitive cannot find any objects, it returns false.

This is heavily used by the "Food Chain" group of interactions and NPC service sims.

id name Object Data Referenced Notes
0 prepare food 31 - Prep Value The food processor has a much better value for this than a counter.
1 cook food 32 - Cook Value Used by food chain after preparation. Oven > Microwave.
2 flat surface 33 - Surface Value Used to find a surface to put anything that isn't food on, like the rose gift you can receive in TS1. Causes the "homework table" effect in TS2.
3 dispose 36 - Dispose Value Used by objects that you can get rid of to find the nearest/most suitable way to dispose of them. Trash compactor > bin > outside bin.
4 eat N/A No value for this, probably just selects first object with food function set.
5 pick up from slot N/A Used by a person to pick up an object.
6 wash dish 37 - Wash Dish Value Finds somewhere to wash dishes. Would prefer a dish washer to a sink.
7 eating surface 38 - Eating Surface Value For instance, a dining table will be more suitable to eat on than a desk.
8 sit N/A Most likely selects the chair with the highest comfort advertisement.
9 stand N/A PersonGlobals::stand up only uses Run Functional Tree with this function, and uses the person's current Container ID to determine what the chair is. This is probably unused.
10 serving surface 61 - Serving Surface Value Used by people who are looking for a place to drop/serve food. A counter or table are usually the best choice.
11 clean N/A Used by Maid to find objects with a clean function available.
12 gardening 64 - Gardening Value Used by Gardener and when normal Sims water plants (to lead onto the next one).
13 wash hands 65 - Wash Hands Value Used by Toilets etc. to find a sink to use for neat sims.
14 repair N/A Used by Repairman to find objects that need repairing.
Offset: 0 1 2 3 4 5 6 7
Meaning: Function Unused

15 - Break Point

Pauses execution for further examination if the variable specified by a Scope is not 0.

Offset: 0 1 2 3 4 5 6 7
Meaning: Data Field Owner Unused

16 - Find Location For

Finds a location to place the stack object. Can be along object vectors, out of the world and "smoke cloud", a specific mode used for the attack interaction.

Offset: 0 1 2 3 4 5 6 7
Meaning: Mode Local # Flags Unused
The possible modes are:
id name notes
0 Default Places as close to reference object as possible.
1 out of world Places the object out of the world.
2 smoke cloud A special mode used for the attack interaction. Most likely places cloud in middle of two attacking sims.
3 along object vector Along the vector the reference object's direction makes.
4 lateral to object vector Along the vector perpendicular to the reference object's direction vector.
id name notes
0 Use Local as Ref Obj Uses the object in the specified local (Local #) as the reference instead of the thread owner.
1 allow intersection The placement can happen inside another object if this is set.
2 user editable tiles only The placement can only happen on tiles accessible by Buy/Build mode if set.

17 - idle for input

Behaves like the sleep primitive, but can return early if the object has been "notified" out of idle, in which case it also sets Object Data flag 1«6 "notified by idle for input". One example of this is when an interaction is canceled, or when another object uses the primitive "Notify the Stack Object out of Idle". This is commonly used (with a sleep time of 0) to detect if an interaction has been canceled.

Offset: 0 1 2 3 4 5 6 7
Meaning: Local # Allow Push? Unused

Local # specifies the Local Variable the number of ticks are taken from. If "Allow Push" is set to 1, this state is "interruptable" and functions can be pushed onto the stack.

18 - Remove Object Instance

Removes the object instance specified.

Offset: 0 1 2 3 4 5 6 7
Meaning: TargetObj Flags Unused

TargetObj: 0 = Me, 1 = Stack Object, 2 = Target (unused)

id name notes
1 return immediately If set, the rest of the function is not allowed to run.
2 cleanup all "Clean up all objects involved"
3 unused
4 unused
5 unused
6 unused
7 unused
8 unused

19 - make new character

Makes a new character with the specified Age, Skin Color and Gender. Not used by any objects activated in TSO.

Operand (not confirmed)
Offset: 0 1 2 3 4 5 6 7
Meaning: AgeLocal SexLocal GenderLocal Unused

20 - Run Functional Tree

Run one of several types of functions on the stack object. Used to make sims sit down to eat, wash their hands etc as part of an automatic process.
See Primitive 14 - Find Best Object for Function above for a the table of functions that can be referenced.

Offset: 0 1 2 3 4 5 6 7
Meaning: Function Flags Unused

The only flag seems to be bit 1: change icon. This changes the behavior icon to that of the stack object (imagine using toilet, when going to wash hands icon changes for sink.

21 - show string

Presumably used for debug. Some objects show interesting and original strings such as "can't get to the duck", but it doesn't look like these should normally be used. Nothing shows up in The Sims Complete Collection when this primitive is run.

Offset: 0 1 2 3 4 5 6 7
Meaning: String Table # (String ID - 1) Unused

22 - look towards

23 - Play Sound Event

Plays the specified sound event.

Offset: 0 1 2 3 4 5 6 7
Meaning: Event ID Unknown Flags Volume (0-100) Unused
id name notes
1 looped If the sound loops or not.
2 with stack obj as source Use the stack object as the sound's source.
3 no zoom Sound volume does not change with zoom level if set.
4 no pan Sound does not pan to match position on screen if set.
5 auto vary
6 Unknown
7 Unknown
8 Unknown

24 - old relationship

Gets the relationship between two objects. Used by the pool table to determine the player number of people and sometimes used by social interactions to keep track of who people are talking to etc. This is an old system for doing this, but objects still use it.

Offset: 0 1 2 3 4 5 6 7
Meaning: Get/Set Relationship Var Parameter # Affected Parties Flags Unknown

Get/Set determines whether or not the relationship value will be retrieved from or set to the parameter specified by Parameter #. 0 = Get, 1 = Set.
Relationship Var determines the relationship variable to access. Not sure what these are right now - looks like each object has its own specific strings!
Flags: 1 = fail if too small, 2 = use neighbors

25 - Transfer Funds

A more fleshed out version of Alter Budget from The Sims 1, allowing more options such as transfer of funds between people, to maxis, from maxis and to generic objects such as the tip jar! Not sure how this works or what the operand is right now.

26 - Relationship

Tracks "relationship" variables of one object to another. Relationships are kept between avatar-lot transfers (not sure about object relationships), so care will have to be taken when storing relationships to avatars (use avatar id instead of object id).

Offset: 0 1 2 3 4 5 6 7
Meaning: Relationship Var Mode Flags Local # Variable Scope Variable Data

The primitive usually gets/sets the relationship variable into/to the specified variable.


There are 4 modes for the Relationship primitive:
0: from me to stack object
1: from stack object to me
2: from stack object to object in local (Specified by Local #)
3: from object in local to stack object (Specified by Local #)

id name notes
1 use neighbor ids Used to get and set relationships to sims off of the lot in the sims 1. Not used in TSO.
2 fail if matrix is not large enough If unset, a new relationship is created when this happens. (maybe means "fail if relationship doesn't yet exist"?)
3 get/set If set, relationship is set to the value in the specified variable. If unset, the relationship is retrieved into it.

27 - Go To Relative Position

28 - Run Tree by Name

This primitive runs the tree referenced by the name in the specified string on either the stack object or itself.

Offset: 0 1 2 3 4 5 6 7
Meaning: String Table ID for Tree Names String Scope (1: global, 0: private) Unused String# - 1 Destination Unused
Destination Values:

0: run in my stack (non-yielding)
1: run in stack object's stack (non-yielding)
2: push onto my stack (yielding)

29 - Set Motive Change

Sets a motive to change at a specific rate until it hits the specified value. You can clear all changes by setting the Clear All? flag.

Offset: 0 1 2 3 4 5 6 7
Meaning: PerHrOwner StopValueOwner Target Motive Clear All? PerHrData StopValueData

The values for the change per hour and value to stop at are accessed via Scopes. If Clear All? is set, all motive changes on this sim are cleared. The Target Motive uses the same ID format as Motive Data.

30 - Syslog

Used to log information from objects. Seems to always log a string from private String Table 308.

31 - Set to Next

Sets the specified variable referenced by a Scope to the object ID of the first object it can find (after the last one) using the search parameters. Used to iterate over objects of a specific type, people etc. Returns false after all objects of that type have been iterated over.

Offset: 0 1 2 3 4 5 6 7
Meaning: GUID (if applicable) Mode LhsOwner Value LhsData
id name notes
0 object Every object (including people)
1 person Just people.
2 non-person Just ordinary objects.
3 part of a multi-tile object Should be in the correct order.
4 object of type Uses GUID field to specify object type.
5 neighbor id
6 obj with category == sp 0
7 neighbor of type Uses GUID field to specify neighbor type.
8 obj on same tile Used counters most often, but also destroying objects fires are inside.
9 obj adjacent to object in local Local specified by value field.
10 carreer (sic) Used to iterate over careers in TS1 for the job finder. Not used in TSO.
11 closest house Not used in TSO. There's a holdover from this though in beds2::Dream Person, presumably made sims dream about neighbours.

If the highest bit (128) of the Modes field is set the left hand side field is used. If not then the object ID is stored in the stack object.

32 - Test Object Type

Tests an object's type against a specified GUID.

Offset: 0 1 2 3 4 5 6 7
Meaning: GUID TargetData TargetOwner

33 - find 5 worst motives

Places 5 worst motives into temps 0-4. Each temp references a Motive Data entry, and they are ordered by lowest first. Only used twice in TSO… npcportal.iff and pedportal.iff (for determining why a sim decided to leave).

Offset: 0 1 2 3 4 5 6 7
Meaning: Unused Target Motive Type

Target: 0 = me, 1 = stack object, 2 = target object (?)
Motive Type: 0 = Motive, 1 = Mental Motive, 2 = Physical Motive

34 - ui effect

Only used by tutorial to flash buttons.

35 - Special Effect

Shows a Picture in Picture display on the specified object (always the stack object). Can also center the camera on an object and slow time down to 1 speed (like the fire).

Offset: 0 1 2 3 4 5 6 7
Meaning: Timeout (seconds) Window Size Zoom Level Flags (Caption STR# - 1) Unused

Window Size: 0 = small, 1 = medium, 2 = large
Zoom Level: 1 = near, 2 = mid, 3 = far

The caption is always read from string table 305.

id name notes
1 activate If unset, the primitive clears the current PIP window.
2 live/one frame 1 = live: shows live window of event. 0 = one frame: shows static picture of event at call time.
3 ignore visibility
4 center If set, the main screen is also centered on the event.
5 snapshot If set, a snapshot will be taken and saved of the event.
6 timeout as Local Variable If set, instead gets the timeout from the Local Variable referenced by the timeout field.
7 slow down Slows the game down to normal speed for events that require quick actions. Not relevant in TSO…
8 unknown

36 - Dialog - Private Strings

Very complicated, not much info on this one and the text exported versions seem to be missing a lot of info. I probably won't be able to get the operand for this one until much later.

Dialog Types:
id name notes
0 message Displays a dialog with a message and yes button.
1 yes-no Displays a dialog with a message, a yes button and a no button. Returns true on yes and false on no.
2 yes-no-cancel Same as above, but on "No" the primitive returns false and sets the specified temp to 0. Cancel returns false and sets the temp to 1.
3 text entry Displays a dialog with text input and OK. The next call to "make new character" will use the input as the name of the new character. (used for babies in ts1, pets in tso?) Has behavior relating to Temps in some way…
4 Sims1.0 tutorial The dialogs that pop up in the sims 1 tutorial. Deprecated in TSO!
5 Numeric Entry Puts the result in the specified Temp. Can use TempXL instead (for biiig numbers). Used for tip jars.

Text Entry also has a "filter profanity" flag which causes the text entry to return false on detecting any profanity. Temp can either be 0 or 1.


Engage (OLD) - ???
Continue (OLD) - ???
Engage - ???
Continue - ???

Not sure what the difference between these is. Both are used in their fair share of dialogs.

id name notes
0 automatic This is the only type used in TSO.
1 none Not used.
2 neighbor Not used.
3 indexed Takes a value, possibly attribute. Not used.
4 named Not used.

Strings can be set for the Message, Yes Button, No Button, Title, Cancel Button and Icon Name. Each presumably takes up a byte in the operand to reference the relevant string id, leaving 2 bytes for the other data… This will most likely be complicated. Strings are always chosen from string table ID 301 (called "Dialog prim string set").

Do not take any information in this section as final!

Local reference

Local variable to reference.

37 - Test Sim Interacting With

Returns true if this sim is interacting with the Stack Object, false otherwise. Used to allow interactions like "wake up" for sims already sleeping in the tent and disallow it otherwise.


No Operand.

38 - Dialog - Global Strings

Same as 36 except instead accessed global strings. TSO only.

39 - Dialog - Semi-Global Strings

Same as 36 except instead accessed semi-global strings. TSO only.

40 - OnlineJobsCall

Calls one of the built in functions relating to OnlineJobs. Any that require input, like "Is Job Available" use the value in temp 0.

Offset: 0 1 2 3 4 5 6 7
Meaning: Call# Unused
id name notes
0 Goto Job Lot Sends the Sim in the Stack Object to their Job Lot.
1 Set Controller ID Sets the controller ID to the ID in the stack object. Used by each respective job controller.
2 AttemptToValidateWorker Returns true if sim works on lot, false otherwise. Used by OnlineJobs doors to block sims that aren't employed.
3 Unused
4 Unused
5 AddStatusMessage Temp 0: String List to use, Temp 1: String ID to use
6 RemoveStatusMessage Removes the current status message
7 SetTimeRemaining Temp 0: Minutes, Temp 1: Seconds.
8 Get Random Job Gets a random job that is available.
9 Is Job Available Checks if the job referenced by Temp 0 is available. Returns true or false.
10 Signal Job Type Change Updates Server info with new Job ID (The one in Person Data, "OnlineJobID")
11 Signal Job Grade Change Updates Server info with new grade (The one in Person Data, "OnlineJobsGrade")
12 SetWorkMode Sets the work mode to the value of the Job Controller's attrWorkMode attribute.

41 - Set Balloon/Headline

Sets the balloon over a Sim's head to display with the specified icon or clear.

Offset: 0 1 2 3 4 5 6 7
Meaning: Target Icon # Icon Group Duration (Ticks/Loops) Balloon Type Flags

Target: 0 = Me, 1 = Stack Object

If Ticks is 0, the Balloon/Headline is cleared. If Ticks is -1 (all bits set), the duration will be forever

id name notes
1 show when inactive
2 crossed out Sets the icon to be crossed out. Used to say things like "no money".
3 animation reversed Reverses the balloon's animation.
4 loops If set, duration will be in animation loops instead of ticks.
5 + Local Variable 0 Adds local variable 0 to the Icon #.
6 unused
7 unused
8 unused
Balloon Types
id name notes
0 Thought
1 Scream
2 Speak These have animations?
3 None Used for things with no backgrounds like the relationship plusses.
Balloon Icons

See Balloon Icons for a list of these.

42 - Create New Object Instance

Creates a new Object Instance with the GUID specified in the location specified. The new object ID is placed in the stack object. If the object cannot be created, the primitive returns false.

Offset: 0 1 2 3 4 5 6 7
Meaning: GUID Position Flags Local To Use (if specified) Interaction Callback
Interaction Callback

Upon running the init function of the created object, if the Return immediately flag is set the Interaction specified by Interaction Callback is queued onto the Stack Object (at the time and same thread this primitive was run) with its Parameter 0 set to the object ID. This is used extensively by the social interaction objects to create AND INIT the objects before running the function from them. This functionality replaces the default where the new object is placed into the stack object, but the primitive still returns true or false depending on whether the creation succeeded or not.

A value of 254 means "Call This Tree".

id name notes
0 in front of me
1 on top of me
2 in my hand
3 in front of stack object
4 in slot 0 of stack object
5 underneath me Apparently only for walk-overable-objects. Not sure if it works otherwise
6 out of world Object ID is in stack, so it can still be controlled and positioned manually.
7 below object in stack param 0 Uses the Local To Use field in some manner…
8 below object in local References object in the specified local variable.
9 next to me in direction of local References object in the specified local variable.
Flags (bitfield)
id name notes
0 do not duplicate
1 pass object ids to main Edith strings describe this as: "transfer current stack object to new object and put my id in stack param 0"
2 use neighbor in stack obj Obsolete apparently… disregards the GUID and creates a visitor using the neighbour in the stack object. (TS1 only?)
3 fail if tile is non-empty
4 pass temp 0 to main Assuming this puts this thread's temp 0 into the new object's temp 0 on init.
5 flag 32 face same direction as stack object?
6 Return Immediately See Interaction Callback above.
7 Persist new object in DB? objects with this unset probably wouldn't be there upon reloading the lot.

43 - drop onto

Drops an object from the specified slot of the Me object onto the specified slot on the Stack Object.

Offset: 0 1 2 3 4 5 6 7
Meaning: SrcSlotMode SrcSlotNum DestSlotMode DestSlotNum

The mode determines where to get the slot number - 0 for literal and 1 for retrieval from a parameter.

44 - Animate Sim

Plays an animation on the thread this primitive is run on's Sim. After playing the animation the primitive acts as an event listener, calling the false branch when an animation event (xevt) is called and the true branch when the animation is finished, and waits in place until one of these happens. When looped back to from the false branch and still playing the animation the primitive will resume event listening. If there have been multiple events since the last time the primitive was listening, it favors the most recent one, or if the animation has already ended, the true branch.

Offset: 0 1 2 3 4 5 6 7
Meaning: Animation ID LocalEventNumber Source Flags ExpectedEvents

ExpectedEvents should be set to the number of events in the animation, but can be set to 0. If it is 0, it has no effect.
If Animation ID is 0, the current animation is stopped.

Animation Source
id name real source
0 This Object STR# 129 for adult/pet, STR# 130 for child.
1 Global STR# 128 in Globals.iff
2 Person Stock STR# 130 in Globals.iff
3 Miscellaneous STR# 156 in Globals.iff for adult/pet, STR# 157 for child (child unused in TSO)
id name notes
0 flag1 unknown
1 backward Set if the animation should be played backwards.
2 param If set, the animation ID is retrieved from param[Animation ID]. If not set, the animation is retrieved from the literal Animation ID.
3 interruptable If set, animation will interrupt when notified by input (eg. action cancelled)
4 flag5 unknown
5 dest Normally on receiving events, the event is stored in parameter 0, however if the dest flag is set the event is stored in local[LocalEventNumber].
6 flag6 unknown
7 unused
The "unknown" flags are:
- Interruptable
- Hurryable
- Full Reset
- Behaviour: A 2 bit collection of animation modes, which are:
id name notes
0 Play and wait The normal mode as described above
1 Set custom background animation Sets the animation that plays when no other animation is playing.
2 Set custom carry animation Carry animation plays on upper half of body when walking, doing most things. Overlays hand animation for all other animations.
3 Stop standard carry, play and wait

Since the only 2 bit space is 3&4, this probably fits in there.

45 - Go To Routing Slot

46 - Snap

Instantly moves the sim to a position retrieved from a routing slot without walking the sim there. Used for objects which move the sim using custom animations (or to positions inside them and back out), like stairs.

Offset: 0 1 2 3 4 5 6 7
Meaning: Index Mode Flags Unused

The Snap to Routing Slot primitive has multiple modes which allow the primitive to do a variety of things:

0 - Slot Number in parameter:
Snaps to a routing slot (type 3) owned by this object, with index specified by the parameter specified by the "Index" part of the operand.

1 - Be contained in stack object:
Snaps the sim into containment slot 0 (type 0, index 0) of the stack object. If the object is dragged while in this state, the sim will be attached to the object like a plate is on a table.

2 - Be in front of the stack object:
Snaps the sim to be directly in front of the stack object. Direction is supposedly unchanged.

3 - Slot Number:
Snaps to a routing slot (type 3) owned by this object, with index specified by the "Index" part of the operand.

4 - Slot Number:
Snaps to a global routing slot (type 3), with index specified by the "Index" part of the operand.


1: Origin only
2: Ask person to move (asks sims idling on the snap location to move)
3: Use footprint extensions (???)

47 - reach

Plays the appropriate reach animation on the sim depending on object height and if the sim is sitting, and can attempt to grab/drop an item on its animation event.

Offset: 0 1 2 3 4 5 6 7
Meaning: Mode Attempt to grab/drop? Slot Param Unused

Mode can be:
0: Reach to stack object, 1: Reach to slot on stack object, 2: Reach to mouth (unused)

When mode 1 is specified, the slot to reach to is retrieved from the parameter specified by "Slot Param".

48 - Stop ALL Sounds

Stops ALL sounds (yes, ALL!) of the specified object.

Offset: 0 1 2 3 4 5 6 7
Meaning: Target Unused

Target: 0 = me, 1 = stack object.

49 - Notify the Stack Object out of Idle

Signals the Stack Object out of an idle primitive. Works for both idle for input and Sleep. Counters and Fence Objects usually use this to notify other fence objects to change their appearance, but some other objects use it to facilitate group interaction around a single animated parent object (eg. the pool table).


No Operand.

50 - Add/Change the Action String

Changes the current interaction's name to the specified string.

Offset: 0 1 2 3 4 5 6 7
Meaning: String Table ID Unknown (String# - 1) Unused

51 - prim 51 - (used in Sims 2.0)

This primitive isn't used in any of the behaviors found in The Sims Online.

52 - prim 52 - (used in Sims 2.0)

This primitive isn't used in any of the behaviors found in The Sims Online.

53 - prim 53 - (used in Sims 2.0)

This primitive isn't used in any of the behaviors found in The Sims Online.

54 - prim 54 - (used in Sims 2.0)

This primitive isn't used in any of the behaviors found in The Sims Online.

55 - Sync Field

This primitive isn't used in any of the behaviors found in The Sims Online.

56 - Ownership

This primitive isn't used in any of the behaviors found in The Sims Online.

57 - Start Persistant Dialog

This primitive isn't used in any of the behaviors found in The Sims Online.

58 - End Persistant Dialog

This primitive isn't used in any of the behaviors found in The Sims Online.

59 - Update Persistant Dialog

This primitive isn't used in any of the behaviors found in The Sims Online.

60 - Poll Persistant Dialog

This primitive isn't used in any of the behaviors found in The Sims Online.

61 - Send Maxis Letter

62 - Invoke Plugin

Used to hook an object into a plugin UI, aka an EOD. This is used for interactions such as the pizza table.

63 - Get Terrain Info

Gets information on the terrain at the position of a specified object. Can either be Me or the Stack Object. (decided by flags)

Offset: 0 1 2 3 4 5 6 7
Meaning: Mode Flags Unused
id name notes
0 Four altitudes around object (temp 0-3) Unknown order, unable to verify, not used.
1 Slope at object (temp 0-1, interpolatable) Puts the X slope in 0, Y slope in 1. +slope indicates down towards that direction. Likely is difference between altitudes, default 0.
2 Fixed coordinates of object (temp 0-4) Put into temps in order: Tile X, Sub-Tile X (0-15), Tile Y, Sub-Tile Y, Level
3 Grass height under object (temp 0) 0-255, Dirt-Grass
4 Ceiling or roof exists above object (temp 0) 1/0 = true/false
id name notes
1 Bi-linear Interpolation If set, bi-linear interpolation is used for the slope mode.
2 Use Me instead of Stack Object If set, the object uses the caller instead of the Stack Object.
3-8 N/A Operand only has the two above flags.

64 - Leave Lot and Goto

This primitive isn't used in any of the behaviors found in The Sims Online.

65 - Find Best Action

Same as TS1 Find Best Interaction, though Free Will was never included in TSO so this primitive was initially replaced with Report Metric. This finds the "best" interaction the sim can perform, eg. the one with the highest advertisments for their lowest motives and other factors. Used for cat and dog free will. Presumably just pushes it to their queue once it finds one, since I can't find anything that queues it afterwards… Returns false when no interaction is found (the sim is suitably satisfied with their current motives, or there is no object to cater to them).


No Operand.

66 - Set Dynamic Object Name

67 - Inventory Operations

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