Status effects are mechanics that alters an entity's behavior or stats. They can be inflicted on both the player and enemies.
Ignite
Ignite is a damage-over-time (DoT) status effect that can be afflicted by anything aflame. This effect lasts for a few ticks and damages on each tick. It can be removed by stepping into water. Walking on oil resets the effect, making it last longer. It can be caused from Fiery Uberglomp, Fiery Glomp and Gargoyle's attacks, all enemies when 
Salamander's Wrath is active, stepping on burning oil, stepping on fire pools, jumping on Torches, and getting hit from wall lanterns and Torches when the 
Waking Light curse is active.
Fiery Glomps, Fiery Uberglomps, and Gargoyles cannot be set on fire.
The player can inflict Ignite on enemies with 
Salamander Tail, Firebird's attacks, throwing the pickaxe through fire, or imbuing the pickaxe with Seertooth.
As it is fire damage, it can be weakened or negated with Gordon's Tunic or by taking a level 2 or 3 Firebird on a run.
Lava Walkers and 
Helios Boots provide immunity from Ignite from standing in fire pools and burning oil.
Oiled
Oiled is afflicted when standing in oil. the entity cannot jump and moves slower. It can be prevented by possessing the 
Galoshes or Helios Boots.
Poison
Poison is a DoT status effect that damages the entity for a few ticks on each tick and significantly slows it down. It can be inflicted by Vilepots, Spiders, Wolf Spiders, Toxic Scales and other Scales in their presence, and all enemies when cursed with 
Venomous.
Poison can be inflicted on enemies with 
Crippling Poison and 
Toxin.
Electrified
Electrified is afflicted when in electrified water. It is removed when the entity moves out of water. Lightning Mites and Mortar's orbs can electrify water.
The player can electrify enemies, which creates chain lightning between some enemies. If the enemy is standing on water, it will temporarily electrocute the water as well. The player can electrify enemies by imbuing the pickaxe with Electrorock, taking the Thunderbird on a run, or the 
Bottled Lightning.
The damage can be reduced if the player has a level 2 or 3 Thunderbird or 
Gordon's Tunic.
Lightning mites will not take electrical damage, but can chain lightning upon hit to other enemies.
Broken Armor
Broken Armor is an enemy-exclusive status effect. It can be inflicted on enemies with the 
Cracked Orb. It causes afflicted enemies to take more damage from all sources.
Blessed
Blessed is an enemy-exclusive status effect. The Ardor Priest can bestow it onto other enemies, temporarily increasing their HP and damage.
War Paint
War Paint is a player-exclusive status effect. It temporarily increases movement speed and damage by killing enemies.