Type Effectiveness

When a move hits a Pokémon, the damage is multiplied by how effective the move's type is against the defender's type(s). If the defender has two types, the multipliers multiply (e.g. 2× × 2× = 4×).

Charizard against a wild Nidoking: damage numbers rise from the target

Multiplier	Meaning	Damage number colour
0×	immune (takes no damage)	no number
¼×	very resistant	123 dark grey-blue
½×	resistant	123 grey-blue
1×	normal damage	123 white
2×	super effective	123 gold
4×	double super effective	123 orange

Effectiveness and critical numbers carry a caption above them: Super! (2×), 4x! (4×), Resisted (½× and ¼×) or CRIT!.

Beyond effectiveness, the number also tells you what happened: 123 critical hit (light gold, never merges with another number), +123 heal (green is for heals only) and Miss miss (the move failed or the target dodged).

The chart below is generated straight from the server's table (pokemon_types.lua). Row = attacking type, column = defending type.

ATK ↓ · DEF →
Normal											0					½		½
Fire		½	2×			2×		½	2×				½			½		2×
Grass		½	½		2×	½		2×				½	½		½	2×		½
Electric			½	½	0			2×					½		2×
Ground		2×	½	2×		½						2×			0	2×		2×
Bug		½	2×				2×			½	½	½		½	½		2×	½
Psychic							½					2×		2×			0	½
Water		2×	½		2×			½					½			2×
Ice		½	2×		2×			½	½				2×		2×			½
Fairy		½										½	2×	2×			2×	½
Ghost	0						2×				2×						½
Poison			2×		½					2×	½	½				½		0
Dragon										0			2×					½
Fighting	2×					½	½		2×	½	0	½			½	2×	2×	2×
Flying			2×	½		2×								2×		½		½
Rock		2×			½	2×			2×					½	2×			½
Dark							2×			½	2×			½			½
Steel		½		½				½	2×	2×						2×		½

Legend: blank = 1× (neutral) · 2× super effective · 4× doubly effective · ½ resisted · ¼ strongly resisted · 0 immune