Entity limit

For reasons of memory allocation, there is a limit to the number of entities Source can manage at once.

Warning:A high entdata may lead to your map and server crashing, avoid high numbers of entities.

Engine limits

There can be up to 4096 entities. This total is split into two groups of 2048:

1. Non-networked entities, which exist only on the client or server.dll (e.g. death ragdolls, logicals).
2. Entities with associated edicts, which can cross the client/server divide.

If the game tries to assign a 2049th edict it will exit with an error message, but if it tries to create a 2049th non-networked entity it will merely refuse and print a warning to the console. The logic behind this may be that an entity spawned dynamically (i.e. not present in the map) but not assigned an edict probably isn't too important.

The two entity lists are created by CBaseEntityList::CBaseEntityList() using NUM_ENT_ENTRIES and MAX_EDICTS. Neither of those values can be changed without breaking compatibility with the engine.

Tip:Temporary entities do not count toward either limit.

Tip:If you're creating lots of individual objects all the time, consider rolling them all into a single manager entity. This is how Left 4 Dead handles huge numbers of infected: they are all "finger puppets" of the director.

Hammer limits

Hammer itself has no entity limit, but VBSP's is 8192. This is double the combined total accepted by the engine,

Confirm:which may be because it at first treats internal entities (such as prop_static and env_cubemap) like normal entities, and/or possibly because it generates a lot of detail props.

VBSP places a size limit of 384KB on the entdata block however, which prevents any map from coming anywhere near 8192 designer-placed entities. Remember that more entities will exist in a map at runtime than were compiled into it by the level designer!

Tip:Since VBSP's source is included in the SDK, it is perfectly possible to make your own build with the entdata limit increased or removed.