In Pokemon, moves have a Primary effects and Secondary effects.
A Primary effect is the effect that is guaranteed to happen if the move hits. Primary effects include; damage, status (Stun Spore, Sleep powder, Will-o-wisp, Outrage, Petal Dance. etc.), recoil damage (Double-edge, Submission), stat modifiers (Close Combat, Hammer Arm, Growl, Tail Whip. Etc.), trapping (Wrap, Fire Spin, Magma Storm), Hp restoration (Mega Drain, Leech Life, Softboiled, Recover. etc.), OHKO (Fissure, Guillotine, Sheer Cold) or other effects such as Rapid Spin/Defog's ability to remove entry hazards or Fake Out's flinching. Any effect that is guaranteed to happen if a move lands is a Primary effect.
A Secondary effect is any effect that has a chance of happening. Secondary effects include; Status (Ember, Psybeam, Tri-Attack, etc.), stat modifiers (Psychic, Shadow ball, Ancient Power. etc.), flinching (Bite, Dark Pulse, Air Slash. Etc.), increased critical hit rate (Slash, Night Slash, Psycho Cut. Etc.), or other effects (none come to mind particularly). A secondary effect is more like a side effect.
I'm wondering just what Encourage's boost will be. And whether or not it will be a one time boost, say, Thunder Fang getting a 20% power boost and losing both the flinch and paralysis chance, or a multiple boost, Thunder Fang getting 20% for losing the flinch rate and another 20% for losing the paralysis. The second thought would definitely increase the viability of the fang moves (93 base power before stab), as well as making Tri-Attack much stronger (base 138 move with 100% accuracy and no downsides).