Packet research

Packet Research

Overview

ID	Purpose	Param	Packet Structure	Size	Notes
0x03	?Spawn minion				Notes on structure
0x11	End Spawn			0x1
0x15	Set Ability level
0x17	Create Effect	EntID	Structure	variable	Has two structures, see notes
0x21	?Death recap data
0x22	Gold Reward
0x2A	Summoner data	EntID		0x212
0x46	Player stats	EntID		0x128/0x120
0x4C	Player header	0		0xC3
0x54	Synch Version	0
0x5B	?Backport
0x5E	Start deathtimer	EntID	Structure	0x12
0x61	Move command		see below	0x152
0x62	Start Spawn	0	unk1: uint16?	0x2
0x63	Spawn jungle			0x152
0x65	Damage Done
0x68	Chat message			variable
0x6B	?Cast summoner
0x6F	Purchase item	EntID	Structure	0x8
0x85		EntID	Structure	0x0a	Structure tentative, see notes
0x92	Game ID	0	Structure	0x88
0x9D	Tower header	EntID		0x4A
0xC1	Update gametimer	0	timer: float	0x4
0xC4	Char Stats	0		variable
0xE4	Gold gain

Type legend:

Structure:

• name: type
• name(?): type - Field may have different meaning
• (name: type)? - Structure uncertain, field may not actually be contained in packet

Symbol	Name	Size in bytes
b	byte	1
i/u8	(u)int8	1
i/u16	(u)int16	2
i/u32	(u)int32	4
f/float	float	4
eid	Entity ID	4
cstr	String (null-terminated)	variable
str	String (length-prefixed)	variable

Extended structure

0x17 - Create Effect

Offset	Name	Type	Notes
0	effectId(?)	u16
2	name	cstr	Sometimes, format differs, see notes

0x5E - Start Deathtimer

Offset	Name	Type	Notes
0	unk1	i32	Usually 0
4	unk2	i32	Usually 7
8	duration	float
12	unk3	u16	Usually 0x4c00

0x61 - Move command

• Shows unit location when they start a new movement, and the location they are headed

• Mostly useful for extracting position data but isn't updated constantly, i.e. when someone clicks to move across the map and waits the entire time to arrive (though you could calculate this given the movement speed)

• blocktype: 0x61

// x and y coords are relative to the center of the map (i.e. the middle of the map is x=0, y=0)
ff ff ff ff // time as a float from game begin
01 // number of units associated with this packet (numUnits)
00 // magic zero?, or maybe will populate if the number of units > 0xff somehow
// repeated struct : numUnits
  02 // number of coordinates for unit (numCoords)
     // if 3 coords, 2 coords expected?
     // if odd number of coords (besides 3), first bitmask byte will be 0xff and will not start with lsb, but numCoords%8 lsb (so if 5 coordinates, will start with the 5th lsb), corner case, may be incorrect
  19 00 00 40 // entity id
  // repeated struct : (floor((numCoords - 2)/8))
    ff // bit mask for absolute or relative position
  ff ff // starting x coords, signed 2byte
  ff ff // starting y coords. signed 2byte
  // repeated struct : numCoords/2 (really repeats : numCoords times, but each coord alternates between x and y, so struct is twice as big, and there may be a spare coord at the end in odd cases)
    ff, ff ff // x coord, dependant on bitmap
    ff, ff ff // y coord, dependant on bitmap
              // if bitmask bit is 1, relative position (signed 1 byte)
              // if bitmask bit is 0, absolution position (signed 2 bytes)
              // bitmask starts with (first byte after entity id, lsb -> msb) -> (following bytes, lsb -> msb)
  // if numCoords is odd (besides 3), will have extra coord that doesn't belong to x or y, see not from previous struct
  ff, ff ff // unknown coord, dependant on bitmap

0x6f - Purchase Item

Offset	Name	Type	Notes
0	entityId	eid	Tentative
4	itemId	u32
8	slotId	u8
9	countOnSlot	u16
11	unk1	u8

0x85 - Unknown

Offset	Name	Type	Notes
0	counter	u8
1	unk1	float(?)	Usually 0, sometimes values between 0 and ~200
5	unk2	float	Always -1

0x92 - Game Id

Offset	Name	Type	Notes
0	gameId	u64
8	unk1	b[80]

Notes

0x03 - Minion Spawn

• Sample captures (one line per capture):

de 00 00 40 40 36 b8 53   ff 00 00 00 00 0a 00 01
df 00 00 40 40 4c 36 eb   ff 00 00 00 00 0a 00 01
e0 00 00 40 40 71 71 b7   ff 00 00 00 00 0a 00 01
e1 00 00 40 40 e8 00 ba   ff 00 00 00 00 0a 00 01
e2 00 00 40 40 af c9 5e   ff 00 00 00 00 0a 00 01

• Looks like [marker byte] [float] [float?] [float] [short] [byte]

0x17 - Create Effect

• Sometimes, not a plaintext names is transmitted, instead it looks like some floats
• Sample captures (one line per capture):

00 06 01 20 00 00 40 
01 06 01 20 00 00 40
02 06 01 20 00 00 40
03 06 01 20 00 00 40

• Looks like [effect id] [marker byte] [some float]?

0x85 - Unknown - Probably Cooldown

• Usually in the form 01 00 00 00 00 00 00 00 80 bf with the first byte incrementing
• Seems to be [slot] [unk1] [float maxCooldown, 0 if = currentCooldown] [float currentCooldown, = -1 if 0]