Every time, when I hear a Metal Gear Solid fan says that splinter cell is a rip off of Metal Gear Solid, I can't help but face palm. I mean have they even payed any closer look to Splinter Cell? And no this isn't a which is better topic, I just want to give my two cents on this issue.
I have played two franchises, and I like stealth games, but coming from experience I do not believe that Splinter Cell is a carbon copy of Metal Gear Solid. I do know Splinter Cell was inspired from Metal Gear Solid, but it doesn't mean it is a rip off.
But if we had to go by this logic that everything inspired is a rip off of it, doesn't that mean the mostly everything is now a rip off? I heard Kojima got the influence to the original Metal Gear from the WWII movie The Great Escape http://www.metalgearsolid.net/features/hideo-kojima-at-the-movies-the-great-escape http://en.wikipedia.org/wiki/The_Great_Escape_(film), but it doesn't make Metal Gear a rip off of that movie. And let me give one of the definitions of Rip off.
(idiomatic) to copy, especially illegally
They ripped off the whole idea from their competitors.
Let me give some arguments why I think MGS fans calling it a rip off is inaccurate at best. Warning this might contain SPOILERS for both MGS and Splinter Cell! So look away if you want. You have been warned.
OK let me cover the basics, gameplay. The only thing similar about them of course is the stealth aspect, hence why there stealth games, but how they do stealth is different, but let me cover the similarities first. In both MGS, and Splinter Cell you can walk up to an enemy and take them hostage, the difference here is, that when Snake or Big Boss takes them hostage, they can pat them for ammo or supplies. In Splinter Cell, introduced in the third game Chaos, Sam can interrogate his hostage for info, not every hostage of course, but when he does it's usually pretty damn funny. Obviously you cannot get ammo from your foes.
Actually let me touch on weapons, in the earlier Splinter Cell games,you were restricted to an pistol and an assault weapon called the SC4000, and those were the only weapons you can use. Snake has like an arsenal of them, ranging from sniper rifles, to missile launchers. It wasn't until Conviction did Sam started using more weapons in game play, but even then he was restricted to a pistol, an assault weapon, and some grenades. However that changed in Blacklist when you can equip an non lethal weapon like the stun gun, and the bow, which gives makes Blacklist the only game to carry three weapons.
Back to stealth, both Snake and Sam can crouch for stealth, but Snake can also crawl, something that Sam lacks, as he only crouch, roll or dash.
By MGS 3, camo was introduced as apart of the stealth gameplay, Splinter Cell has no system like that, instead what Splinter Cell does is rely on the shadow and light system, which is like the Thief games, now you can argue if Splinter Cell stole from Thief or not since there very similar.
In the original Splinter Cell games, if you get caught three times the mission ends, thus making things trial and error and was more linear albeit like the older MGS games. But by Chaos Theory they made the environment more open and let's you complete your mission without being terminated if you get three strikes. In Metal Gear Solid you were never penalized which is a plus, instead as you know we get timed on how long the alert lasts to 99 seconds, and theres another 99 second countdown when the enemies are looking for you. In Splinter Cell if you're caught the enemies will be fully alerted even if you disappear, there's no countdown.
Lastly to cover the stealth mechanics, both Sam Fisher, and Snake use goggles to get an advantage of there enemies. However with Sam it's his trademarked tri goggles. With the Tri goggles you can use night vision, thermal vision, and EMP vision. Snake can do the same kind of stuff like with the Solid eye in MGS4.
Snake has a box, Sam doesn't lol.
The MGS games had always an interconnected story that expands most of the games, in the Splinter Cell games, each story is pretty much self contained, and doesn't connect until Double Agent where Sam is now on the run after killing his best friend Lambert who is also his boss. Double Agent's story continues on into Conviction, in Double Agent Sam's daughter was apparently dead, that is not the case and Sam tries to find out why in Conviction.
However there appears to be a Shadowy organization similar to the Patriots, called Megiddo who were the ones that made Third Echelon, the black ops group Sam used to work for, conspire against the president. And they might be the ones who the antagonist of Blacklist Majid Sadiq was working for.
The MGS series had an array of memorable boss fights, Splinter Cell has barely any unless you count taking on the main villains as boss fights in the last levels.
MGS's stories always touched on political, philological, war, and cultural issues. It's story line is also more fantasy and anime inspired like since it's made in Japan. Splinter Cell's stories is more grounded in reality and realism, and has touched from things like cyber warfare, stopping terrorists, and preventing a governmental coup.
MGS's stories in the game are always told thoroughly through prob long cut scenes (But they were very very long in MGS4), while Splinter Cell's are explained through brief cut scenes or dialogue during gameplay.
End spoilers, and arguments.
All in all, this is why I think Splinter Cell shouldn't be regarded as a rip off. It shares some elements with Metal Gear, but it's small and nothing major, and aside from the fact there stealth games. I know it's usually the fan boys bringing this up, but I felt like I needed to explain it.
Splinter Cell and Metal Gear Solid are two good stealth games, but different in gameplay, story, characters etc.
If you feel different about this however, then that's fine. This is my view of them.
And sorry for the long post, trying to make a point requires time
Edit: If I made any errors or mistakes explaining these two games, feel free to correct me.