Arcane Sticky Grenade

The Knock spell is can be used to pick locks and open pathways. However, blowing up the lock and destroying barricades can also open pathways. This spell does the later.

When you cast this spell, you must hold a iron block in your outstretched hand.  Once cast you must either throw or drop the iron block or touch a solid surface with iron block. These count as being part of the action you used to cast the spell and so don't require any additional actions or bonus actions. The iron block will then stick to the surface you touched with it or the first solid surface it touches after you threw it. If you fail to throw or drop the iron bar or touch a solid surface with it when casting the spell, it will stick to your hand.

The iron block does not stick to anything (but it can still explode) if it is submerged in liquid. A creature can use an action to make a DC17 STR check to remove the iron block from the surface it is stuck to. Once removed, the bar loses its stickiness but not it's explosive capabilities.

After the spell has been cast, you may use a bonus action or a reaction to cause the iron block to explode. On your turn, you can also use an action to remove the spell. In this case, the block becomes a normal iron block and so the material component is not consumed. To detonate the block you must be within 200ft of it. You are not required to be in this range if you wish to remove the spell. If you neither detonate the block or remove the spell, the block will explode automatically after 1 minute has passed since the spell was cast.

When the iron block explodes, it damages everything in a 5ft radius from the block. Any creature in the blast radius must succeed a DEX save or take 4d6 Force damage. This spell does an additional 4d6 force damage to constructs and objects.

If you wish to stick this iron bar to a creature, you must make an attack roll against the target using DEX as the ability modifier. The creature can use an action to make a DC17 STR check to remove the block from him. If the iron block is detonated while it is stuck to a creature, the creature automatically fails the DEX save associated with this spell and takes maximum damage.

At higher levels. When you cast this spell using a spell slot of higher level, the damage done by the explosion increases by 1d6 for every level higher than 2nd. If you use a spell slot of 6th level or higher to cast this spell, then the blast radius increases from 5ft to 10ft in addition to the increased damage.