At the outset of its invasion of Ukraine the range of weapons at Russia's disposal was expected to overwhelm its neighbour. But Kyiv has effectively used its more limited arsenal against the larger aggressor.
Dark warnings of nuclear and chemical attacks have also featured since 24 February.
Here are some of the weapons that have come to prominence since the start of the conflict.
Javelin anti-tank missiles
The Javelin anti-tank missile has been credited with boosting the ambush capabilities of Ukraine’s army against Russian armoured columns and more than 15,000 are reported to have been supplied to Kyiv.
Ireland’s Defence Forces also use this weapon.
Javelin is US-manufactured weapon, developed jointly by Raytheon and Lockheed-Martin. It has been in use since 1996. It costs around €185,000 per unit. The weapon can be fired by one person from a shoulder-mounted launcher.
Once the target is selected using day or night sights, its location can be locked-on before being fired. The missile is self-guided, meaning the person who has fired the weapon can move rather than staying in position to guide the missile after it is launched.
The effective range is around 2.5km, although it has been used over 4.5km in exercises. The missile attacks the target from above. On tanks, the hatches on top weaken the armour and make them vulnerable to this mode of attack. The missile is armed with a double explosive charge to pierce armour.
NLAW (Next Generation Light Anti-Tank Weapon)
Manufactured in the Thales factory in Belfast (formerly Shorts), the NLAW is a joint Swedish-UK venture designed by Saab.
Described by Saab as "the ultimate tank killer", it is a light (around 12kg) shoulder-mounted weapon that, like the Javelin, can be fired by one person.
Thousands of the missiles have been provided to Ukraine.
NLAWs can be fired in 'top attack’ mode like the Javelin (i.e. it hits the target from above) or in direct mode against the front, rear, or sides.
At around €25,000 per unit, it is considerably cheaper than the Javelin, but it also has a shorter range of just under 800 metres.
Stinger Surface-to-Air (SAM) anti-aircraft missiles
Stinger is a man-portable air-defence system (MANPADS) mainly manufactured by US arms manufacturer Raytheon.
It can be used by one person against helicopters, drones and aircraft and also against cruise missiles.
Its predecessor, the Redeye, was supplied by the US to the mujahideen in Afghanistan to fight against Soviet helicopters in the 1979-89 Soviet-Afghan War.
They were not supplied to Syrian rebels out of fear they could be used in the West if they fell into the hands of Al Qaeda or groups linked to the so-called Islamic State.
In Ukraine, hundreds have been supplied or pledged by the US and its allies.
Ukrainian armed forces claim they have shot down Russian helicopters using the weapon.
The supply of Stingers to Kyiv is one of the reasons analysts have given for the relatively limited use of Russian air power to date.
The NGO Human Rights Watch said Russia has sent TOS-1A rocket launchers, which fire thermobaric missiles, into Ukraine but it has not documented any specific attack using them.
Human Rights Watch (HRW) arms expert Mark Hiznay described the effects of the weapons as "really, really chilling".
Thermobaric weapons generate more heat and pressure than conventional high explosives and operate like a flamethrower.
They detonate in two stages. The first stage releases a fine aerosol mist of combustible material - like gas, liquid or fine powder - into the air. This fine cloud can penetrate into basements, buildings and bunkers.
The second detonation ignites the cloud, effectively setting the air on fire and sucking in any available oxygen to fuel the ignition.
This creates the vacuum that means they are sometimes called 'vacuum bombs'.
They can be as small as grenades or as large as several tonnes in weight.
"If you're in a building or a cave, there's literally nowhere to hide," Mr Hiznay told HRW's website in a recent interview.
Thermobaric weapons were used by the US in Vietnam, by the Soviet Union and the US in Afghanistan and by Russia in Chechnya.
An early form of the weapon, the Nebelwerfer (which literally means 'fog launcher') was used by Nazi Germany in World War II.
Tactical nuclear weapons
Vladimir Putin warned the international community of "consequences greater than any you have faced in history" if they intervened militarily in Ukraine to halt his invasion.
It was widely seen as a threat to use tactical nuclear weapons.
Russia has the largest nuclear arsenal in the world. Only the United States, which has the second largest arsenal, has used nuclear weapons offensively in a war.
In 1945, they dropped 15 and 25 kiloton bombs on Nagasaki and Hiroshima respectively, to devastating effect.
While tactical nuclear weapons have smaller warheads of about 0.1 to 1 kilotons (strategic nuclear weapons carry warheads of about 100 kilotons), their power should not be underestimated.
"No one should imagine ... that it makes sense to use a tactical nuclear weapon. A thermonuclear explosion of any size possesses overwhelming destructive power ... It would also cause all the horrors of Hiroshima, albeit on a smaller scale," said Brown University nuclear weapons expert Nina Tannenwald in a recent article on the Scientific American.
"A tactical nuclear weapon would produce a fireball, shock waves, and deadly radiation that would cause long-term health damage in survivors. Radioactive fallout would contaminate air, soil, water and the food supply."
T2B Turkish drones
Ukraine has been buying Turkish Bayraktar T2B drones since 2019.
By most estimates, it has about 20 of the unmanned aerial vehicles (UAVs). To what extent they have been used against invading Russian forces is not clear, although Ukraine claims to have used them to destroy parts of the Russian armoured column that stalled in its approach to Kyiv.
They are relatively cheap at about $2m each and can fly for 27 hours at time. Each drone can carry four lightweight laser-guided bombs for use against armoured vehicles.
The T2B drones were used by the Turkish-backed Libyan Government of National Accord against the Russian backed General Khalifa Al-Haftar.
Russian Pantsir surface-to-air missiles were effective against the T2B drones in Libya.
The Turkish drones were also used by Azerbaijan in the recent war with Armenia over Nagorno Karabakh.
Speaking about that conflict, Col Scott Shaw of the US Army's Asymmetric Warfare group told Foreign Policy magazine that drones can act as a leveller between large military powers and smaller ones.
"What’s clear in [the Nagorno Karabakh] conflict is that a less funded nation can do combined arms warfare," Col Shaw said.
"You don't need something like the United States Air Force, a superbly trained, spectacular capability, in order to conduct potentially a local air-to-ground or air-to-air activity."
Cluster bombs are bombs dropped by airplanes, fired by artillery shells or carried by rockets. The larger bomb opens to drop dozens or hundreds of smaller 'submunitions'.
They are highly dangerous to civilians as, apart from the initial explosion, around a quarter of the smaller bombs can remain unexploded.
There have been many incidents of children finding small bombs and suffering devastating injuries. 110 countries, including Ireland, have signed an international treaty against the use of cluster munitions.
Russia and Ukraine are not among them. Human Rights Watch says that Ukraine used them in the 2014-15 conflict with Russian-backed separatists in the Donbas, but has not recorded their use by Ukrainian forces in the current conflict.
Russia used them in Kharkiv and "extensively" in Mykolaiv, the international rights group said.
Chemical and biological weapons
In late March, Russia claimed the US was helping Ukraine to develop biological weapons. Moscow also accused Ukrainian forces of planning chemical weapons attacks.
The claims led the US to accuse Russia of planning attacks of its own and blaming Ukraine.
Both Russia and the US are signatories to the 1993 Chemical Weapons Convention (CWC). Moscow destroyed its declared chemical weapons stocks in 2017.
The use of nerve agents on Kremlin opponents strongly indicates that some undeclared stocks were held in reserve.
The US has destroyed over 90% of its declared stocks and is due to have disposed of the remainder by next year.
Ukraine has no declared chemical weapons stocks. There is a risk of an environmental disaster arising from a strike on a site containing hazardous material.
Shelling in the area around the Chernobyl nuclear power plant raised international concerns in the early stages of the war.
Damage to an ammonia fertiliser plant could result in a poisonous gas leak. There are also thousands of other hazardous sites around Ukraine, such as disused coal mines storing radioactive or other dangerous waste.
The disarmament group PAX in the Netherlands told New Scientist magazine that disruption to power supply near such a facility could stop the pumps that prevent the mines from flooding, thereby contaminating groundwater.
Hypersonic missiles are fast-moving weapons that can travel up to ten times the speed of sound.
They can be launched from rocket launchers on land, from ships or submarines at sea, or from military aircraft in the air.
Their destructive power depends on the type of explosive they carry, up to and including nuclear warheads.
Their flight trajectory is much lower than other large ballistic missiles, meaning they are hard to detect on radar.
Their speed also makes detection and interception by air defence systems more difficult. This is compounded by their ability to change direction en route to the target.
Russia says it has used its Kinzhal (meaning 'dagger') hypersonic missile at least twice since invading Ukraine.
The first strike was on an underground arms depot at Deliatyn in the Carpathian mountains, the second on a fuel storage facility at Kostiantynivka near the Black Sea port of Mykolaiv.
As Russian armoured columns prepared to advance on Kyiv, news bulletins showed civilians all over Ukraine preparing Molotov cocktails.
The Pravda brewery in Lviv repurposed its bottling capacity to produce them on an industrial scale.
They are simple incendiary devices made with glass bottles filled with petrol. A rag in the neck of the bottle is lit and the device is thrown.
Sugar, rubber or polystyrene is sometimes mixed with the petrol to make it stick to its target and burn for longer.
They have been used against tanks since the Spanish Civil War and are still regarded as a useful weapon in urban warfare.
The name has its origins in Finland's darkly humorous response to Soviet fake news.
The USSR's foreign Minister Vyacheslav Mikhaylovich Molotov claimed that bomber planes were dropping food parcels on Finland during the 1939 Winter War.
The Finns responded by dubbing the bombs 'Molotov’s bread baskets'. They said it would be only polite provide 'drinks' to Russians in return, which they called Molotov cocktails.