Challenger 2 DL1 (Dorchester Level 1) (Base Cr2): How indecent!
The base we all love and adore. Equiped only with Dorchester Level 1 protection, that is internal armour, zooms around the battlefeild, not knowing it will soon turn into one of the heaviest MBTs ever!
Challenger 2 DL2E: I will not show you my feets!
Here it starts wearing its first addition armour! Front is protected by Gen 1 plate on the UFP and ROMOR-A ERA. The sides welcome VARMA blocks known and loved from Challenger 1, as well as some steel plates and ruber skirts. Exhaust get covers that redirect fumes to the back.
Challenger 2 DL2F early: Im getting stronger!

Composite blocks now find their way to the turret sides, both it and hull VARMA gets upgraded to 2F standard. Hull VARMA obtain backplates
Spoiler

Sides where the engine get covered by ~20mm plate. Also back and back parts of turret and hull get slats.
Challenger 2 DL2F late: That call will not reach its destination.
UFP add on plate gets upgraded to Gen2 (thiccer), ROMOR-A gets replaced by Chobham block. Loader optics and coupola mount get replaced by ENFORCER RCWS. On the front mudguards and at the back of the turret, ECM is mounted, that prevents remotely detonated bombs from detonating (there were some rumors it could also disrupt ATGMs, but it was not confirmed). NVD cameras are added to the front and the back of the tank, making driver job easier, and the tank gets first generation Barracuda MCS.
Challenger 2 DL2G: Protecting my knees!
Compared to DL2F late, the smaller backplates get replaced by a massive one, 40mm all the way, with 200mm block under the VARMA blocks. Slat armour gets higher, Turret VARMA blocks get upgraded to 2G/2H standard.
Challenger 2 DL2H: Those mines tickle.
The same as 2G, but hull VARMA blocks get replaced with ASPRO-HMT blocks and underneath the tank, a mine protection kit is added.
Challenger 2 DL2I: Damn boy he thicc!
Turret side block get upgraded to 2I standard, as well as getting spaced plates on them
Later it obtained new generation Barracuda MCS
Challenger 2 OES: Im suited for that job.
Rather than a version on itself, it has multiple variants mounted on the same platform

Armor packages can be any of the DL2 versions based on which suits the mission the best.