Rune of repair

A permanent item for your worker, which gives it an aura that repairs 2.5 hp/s to buildings in 700 radius around the worker.
Extremely useful item with "artillery" enabled that can keep parts of your base alive. In "no artillery" mode, it is mostly handy when turtling up to keep the towers at the front healthy. Can be stacked with itself and Coral Statues for increased effect.

Drum'n'Bass Bassline Generator

A permanent item for your worker, which gives it a global aura. The aura increases movement speed of ALL allied units, mechanical included, by 15% and attack speed by 30%.
An expensive item, that despite that, can come in handy fairly early into the game to force your enemies to use more rescue strikes. Buy this when your army needs just more power to assault enemy castle, as the bonus movement speed will make allied reinforcements connect to the main army much quicker. It is a must purchase in almost every game even without early pressure. Additional purchases of this item do not have any effect.

Scroll of Stone

A consumable item for your worker, that is a single cast spell, with large area. It can be used anywhere on the map to heal 400 hp, regain 200mp and apply a +8 armour buff in a set area.
A very handy item in almost every stage of the game. Use it whenever your damaged army is stacking close to enemy walls to turn a weak push into a real threat. Alternatively, use it aid units in your own base to hold long enough for allied reinforments, saving you a rescue strike. Casting this item at the right time is a difference between winning a battle or doing absolutely nothing. The shop can store up to 2 of this item, restocks 1 charge every 180s.

Blast Staff

A permanent item for your worker, which gives it an automatic ability to shoot a 60 spell damage missile at a random target within range.
It is a low dps item without terrible impact on the game but can absolutely save you from losing an early rescue strike in the right circumstances. Early pushes usually take very long to threaten your buildings or castle, in that time period the staff can effectively snipe squishy backline or recovering bears. The targetting is random but you can manipulate that by only having 1 target within the item's range. In niche scenarios it might even be worth to acquire multiple staves but be careful, as spell resistant or healing units/buildings will greatly diminish the usefulness of this item.

Blast Staff

A permanent item for your worker, which gives it a global aura. The aura increases damage of ALL allied units, mechanical included, by 33%.
A great item to have, a must have in most games but due to not buffing movement speed, it is advised to get this global aura after the other one.

Cheese

A consumable item that is consumed instantly on purchase. It increses the limit of legendary buildings/units for a WORKER, so make sure you use the correct worker to purchase it.
A very expensive item which has varied usability depending on the race. It is extremely handy on races like High Elf or Human and quite useless for others. The cost is quite high, on top of the price of another legendary building, which takes away cash you could've invested in units and time needed to save up for it. In some scenarios it might be worth to skip legendary unit to not delay the legendary building, in others the cheese might only further stall the game, despite using it on a good legendary. Lastly, always consider if you're not taking away cheese from an ally that needs it more. The shop has a maximum of 2 of these items and they recharge every 160s.

Orb of Lightning

A permanent item, which gives the worker an ability to cast chain lightning. The spell does 1000 dmg to 10 targets with a cooldown of 60s.
The range is about half of the map, make sure the lightning can chain to all of the targets. It is used to defend, snipe enemy backline or aid your push before it reaches the enemy side. It is quite handy but loses impact in late game. Buying multiple orbs on the same worker is pointless, because all orbs will go on cooldown when one is used but it can be worth to get 3 orbs on 3 different workers. Cannot buy before 10 minutes of a round pass. Shop restocks on this item every 150s.

Double Damage

A consumable item that is used instanly when you get it. Applies an additive +100% damage global aura to all allied units for 30s.
It is a powerful effect but due to the price it must be used with care, spamming it without achieving anything will hurt your economy. Use it either to buff an army near enemy castle or counteract your enemy using this item against you. Keep in mind the effect is usually not long enough to win a battle in the middle and effectively destroy enemy castle. Sometimes this effect is not enough to make a difference, in which case purchasing quad damage at the same time is highly advised. The item in the shop recharges every 120s. The effect can stack with Quad Damage for a total of +400% dmg.

Quad Damage

A consumable item that is used instanly when you get it. Applies an additive +300% damage global aura to all allied units for 30s.
It is a very powerful effect but due to its steep price it must be used with care, spamming it without achieving anything will hurt your economy. Use it either to buff an army near enemy castle or counteract your enemy using this item against you. Keep in mind the effect is usually not long enough to win a battle in the middle and effectively destroy enemy castle. It is powerful on it's own but purchasing Double Damage at the same time can give it an extra edge. This works on already alive units as well as ones that spawn during the duration. The item in the shop recharges every 120s. The effect can stack with Double Damage for a total of +400% dmg.