Target 1 face-up monster on the field; until the End Phase, it loses 800 ATK, but is unaffected by the effects of other Spell/Trap Cards.

Forbidden Lance was first used often in Gladiator Beasts and since then it has not looked back; becoming one of the most used tech cards in the game. So what exactly does this card do? Forbidden Lance is a quick-play spell card that decreases a face-up Monster's attack by 800, in return for it being immune to the effects of other Spells and Trap Cards.

The first aspect to point out is that it is a Quick-Spell; the most versatile type of Spell/Trap card. You can set it during your turn and use it like a Trap next turn, activate it like a normal Spell card from your hand, or chain it to other cards during your turn.; whats not to love? The second point is it's effect; giving a monster full immunity to other Spell/Trap cards is obviously useful.

Forbidden Lance is used to disrupt your opponent's plays; in two main ways. The first way is to stop them from destroying your monster by using Spell/Trap cards; should they use Torrential, Bottomless, Dark Hole, Compulsory (Anything other than Solemn Warning/Judgement pretty much), just chain Lance to your monster and they would've wasted a key card. Don't forget, it can be used against other Spell/Traps (I've seen people miss this part): for example, Gravekeeper monsters with lose 1300 attack (- 500 from Necrovalley - 800 from Lance), if you use Lance on your monster it can attack past Swords or Gravity Bind. The second way is using it to run over your opponent's monsters; you can use this on your opponent's monsters and cause them to lose 800. This makes most monsters manageable to run over: for example, Stardust will drop to a weak 1700. Plus since it decreases attack, it can be used in the Damage Step, and not too many things could stop stuff in the Damage Step. (Hence why you'll see this used with Rabbit utilizing Guaiba)

The only negative aspect about this card is the 800 attack loss. However, given that even that can be used to your advantage Forbidden Lance is one of the most splash-able cards in the game. I know I didn't list all the ways this card is used but it's fairly straightforward. So opinions? Do you use Lance in your Main? Side? Or maybe don't have room for it?

P.S. The COTW until now were mainly about well-known cards; I'll try and fit some more unknown cards in the future.